Sharp R-895(AL)M Service Manual

Page 1
R-895M - 1
TABLE OF CONTENTS
Page
CAUTION, MICROWAVE RADIATION.................................................................................................... 2
WARNING.................................................................................................................................................2
SERVICING ............................................................................................................................................. 3
PRODUCT SPECIFICATIONS ................................................................................................................. 4
APPEARANCE VIEW .............................................................................................................................. 5
FUNCTION OF IMPORTANT COMPONENTS ....................................................................................... 9
TROUBLESHOOTING GUIDE ............................................................................................................... 12
TEST PROCEDURES ........................................................................................................................... 13
TOUCH CONTROL PANEL ASSEMBLY .............................................................................................. 19
MICROWAVE MEASUREMENT ........................................................................................................... 30
SCHEMATIC DIAGRAMS...................................................................................................................... 31
PICTORIAL DIAGRAM .......................................................................................................................... 35
POWER UNIT CIRCUIT DIAGRAM........................................................................................................36
CPU UNIT CIRCUIT DIAGRAM..............................................................................................................37
PRINTED WIRING BOARD OF POWER UNIT DIAGRAM .................................................................... 38
PARTS LIST .......................................................................................................................................... 39
EXPLODED DIAGRAM OF OVEN PARTS ........................................................................................... 41
CONTROL PANEL & DOOR PARTS ..................................................................................................... 42
MISCELLANEOUS/PACKING & ACCESSORIES .................................................................................. 43
S70224R895M//
MICROWAVE OVEN WITH GRILL AND CONVECTION
MODEL
R-895(AL)M
In interests of user-safety the oven should be restored to its original condition and only parts identical to those specified should be used.
SERVICE MANUAL
SHARP CORPORATION
®
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R-895M - 41
OVEN PARTS
7-6
7-18
7-11
7-16
7-8
7-18
7-7
x7
x2
1-18
4-25
4-14
4-26
4-30
4-32
4-27
4-32
4-19
7-12
7-13
7-9
4-3
1-8
4-21
4-24
7-18
7-18
7-18
7-18
4-28
7-4
2-3
7-4
7-15
7-15
4-18
7-18
7-17
7-7
4-1
4-5
1-11
7-18
4-18
4-6
4-4
7-18
1-1
7-7
7-6
1-3
7-6
7-18
6-5
1-3
7-6
1-2
1-20
1-16
1-14
1-15
7-17
7-18
7-18
7-10
7-17
4-7
7-6
6-3
6-5
7-14
7-1
1-10
4-16
1-7
1-17
4-13
4-12
1-4
7-6
7-19
4-29
4-20
7-18
7-18
2-4
2-5
2-5
4-9
4-31
7-3
1-19
4-2
4-15
7-5
7-2
7-2
1-21
7-5
4-10
4-22
4-17
4-11
4-8
6-4
4-23
1-9
1-6
1-5
1-12
6-6
2-2
2-1
1-13
7-5
NOTE: In the event of removing the turn-
table motor cover this part should be refitted using screw connec­tion: LX-EZA045WRE0 (7-20)
OVEN PARTS
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R-895M - 42
CONTROL PANEL PARTS
DOOR PARTS
CONTROL PANEL AND DOOR PARTS
3-4
3-2
3-7
3-7
3-7
3-5
3-6
3-1
3-3
5-4
5-6
5-7
5-8
5-3
5-12
5-11
5-1
5-9
5-9
5-10
5-2
5-5
5-10
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R-895M - 43
'2002 SHARP CORP. Printed in U.K.
PACKING AND ACCESSORIES
®
TURNTABLE TRAY
PRINTED MATTER
ACCESSORY HOLDER
(SPADPA015URE1)
TOP PAD ASSEMBLY
(FPADBA018URK0)
BOTTOM PAD ASSEMBLY
(FPADBA019URK0)
WRAP COVER
(SPADFA353WRE0)
DOOR PROTECTION SHEET
(SPADPA026URE0)
PACKING CASE
SPAKCA437URR0
Not Replaceable Items.
PROTECTION SHEET
(SPADPA024URE0)
BOX MODEL LABEL
TLAB-A310URR0
INTO THE OVEN CAVITY
LOW RACK
HIGH RACK
COPYRIGHT © 2002 BY SHARP CORPORATION
ALL RIGHTS RESERVED.
No part of this publication may be reproduced, stored in retrieval systems, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher.
MISCELLANEOUS
Actual wire harness may be different than illustration.
6-5
6-1
6-8
6-2
6-7
MISCELLANEOUS / PACKING & ACCESSORIES
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R-895M - 39
Note: The parts marked "" may cause undue microwave exposure. / The parts marked "*" are used in voltage more than 250V. / "§" Mark: Spare parts delivery section
REF. NO. PART NO. § DESCRIPTION Q'TY CODE
PARTS LIST
*
*
*
*
ELECTRIC PARTS
1- 1 FH-HZA075WRE0 U Thermistor 1 AN 1- 2 RTRN-A529WRE0 U TC transformer 1 AV 1- 3 QACCBA004URE3 U Power supply cord 1 AT 1- 4 FH-DZA035WRE0 U High voltage rectifier assembly 1 AP 1- 5 FPWBFA309WRE2 U Noise filter 1 AT 1- 6 QFS-CA025WRE0 U Fuse F8A 1 AC 1- 7 QFS-BA009WRE0 U Fuse 20A 1 AC 1- 8 RMOTEA373WRE0 U Convection motor 1 AV 1- 9 RC-QZA240WRE0 U High voltage capacitor 1 AR 1-10 RTHM-A098WRE0 U Thermal cut-out 125˚C off(MG) 1 AH 1-11 RTHM-A124WRZZ U Thermal cut-out 145˚C off 115˚C on (OVEN) 1 AH 1-12 RHET-A255WRZZ U Top grill heating element 1 AT 1-13 RHET-A248WRZ1 U Bottom grill heating element 1 AW 1-14 QSW-MA146WRZZ J Monitored latch switch 1 AC 1-15 QSW-MA147WRZZ J Stop switch 1 AG 1-16 QSW-MA146WRZZ J Monitor switch 1 AC 1-17 RMOTEA002URE1 U Fan motor 1 AW 1-18 RLMPTA066WRE0 U Oven lamp 1 AK 1-19 RTRN-A019URE0 U High voltage transformer 1 BF 1-20 RV-MZA243WRE1 U Magnetron 1 BH 1-21 RMOTDA227WRE0 U Turntable motor 1 AU
CABINET PARTS
2- 1 GCABDA001URP2 U Back plate 1 AQ 2- 2 GCABDA002URP0 U Sub back plate 1 AH 2- 3 GCABUW045URP0 U Outer case cabinet 1 AW 2- 4 GDAI-A002URP0 U Base plate 1 AR 2- 5 GLEGPA057WRE1 U Foot 2 AB
CONTROL PANEL PARTS
3- 1 DPWBFA184URK0 U Power unit 1 BC 3- 1A QCNCMA453DRE0 U 5-pin connector (CN-A) 1 AC 3- 1B QCNCMA414DRE0 U 2-pin connector (CN-B) 1 AB 3- 1C QCNCMA410DRE0 U 2-pin connector (CN-C) 1 AB 3- 1D QCNCMA230DRE0 U 4-pin connector (CN-E) 1 AC 3- 1E FW-VZA266DREZ U 15pin wire harness (WH-1) 1 AH C1 RC-KZA087DRE0 U Capacitor 0.1 uF 50V 1 AB C2 VCEAG31VW108M U Capacitor 1000 uF 35V 1 AE C3 RC-KZA087DRE0 U Capacitor 0.1 uF 50V 1 AB C4-5 VCEAG31VW106M U Capacitor 10 uF 35V 2 AB D1-7 VHD1SS270A/-1 U Diode (1SS270A) 7 AA D11-14 VHD1N4005E/-2 U Diode (1N4005E) 4 AA D11-14 VHD1N4004S/-1T U Diode (1N4004S) (Interchangeable) 4 AA Q2 VSKTA1274//-3 U Transistor (KTA1274) 1 AA Q3 VSKRC243M//-3 U Transistor (KRC243M) 1 AB R2 VRD-B12EF152J U Resistor 1.5K ohm 1/4W 1 AA R3-4 VRS-B13AA511J U Resistor 510 ohm 1W 2 AB R5 VRD-B12EF332J U Resistor 3.3K ohm 1/4W 1 AA R6 VRS-B13AA201J U Resistor 200 ohm 1W 1 AB RY1 RRLY-A117DRE0 U Relay (DU18D1-1P(M)-R) 1 AG RY2 RRLY-A122DRE0 U Relay (DU18D1-1P(M)-R-S) 1 AG RY3-4 RRLY-A113DRE0 U Relay (DU24D1-1P(M)-R) 2 AG RY5-7 RRLY-B004MRE0 U Relay (FTR-F3AA024E) 3 AL SP1 RALM-A014DRE0 U Buzzer (PKM22EPT) 1 AG VRS1 RH-VZA034DRE0 U Varistor (10G471K) 1 AD ZD2 VHEHZ201///-1 U Zener diode (HZ20-1) 1 AB 3- 2 DPWBFC239WRKZ U CPU unit 1 BC 3- 3 FUNTKC135URE0 U Key unit 1 AS 3- 4 HPNLCA123URR0 U Control panel frame 1 AV 3- 5 LHLD-A007URF1 U LCD holder 1 AD 3- 6 PSHEPA647WRE0 U LCD sheet 1 AL 3- 7 XEPSD30P10XS0 U Screw : 3mm x 10mm 6 AA
OVEN PARTS
4- 1 DOVN-A023URK0 U Oven cavity 1 BG 4- 2 LBNDKA107WRP1 U Capacitor holder 1 AD 4- 3 FDUC-A003URY0 U Air duct assembly 1 AL 4- 4 LANGQA005URP0 U Air separate angle B 1 AC 4- 5 PDUC-A636WRP1 U Air guide duct 1 AM 4- 6 PFILWA001URP0 U Lamp filter 1 AB 4- 7 PHOK-A002URF1 U Latch hook 1 AH 4- 8 LANGQA014URP0 U Turntable motor angle 1 AE 4- 9 PCUSUA019URE0 U Cushion 1 AA 4-10 FANGTA003URY0 U Turntable motor shaft assembly 1 AL 4-11 PPACGA002URE0 U Seal packing 1 AB 4-12 NFANJA038WRE0 U Fan blade 1 AF
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R-895M - 40
*
∆ ∆
REF. NO. PART NO. § DESCRIPTION Q'TY CODE
Note: The parts marked "" may cause undue microwave exposure. / The parts marked "*" are used in voltage more than 250V. / "§" Mark: Spare parts delivery section
PARTS LIST
HOW TO ORDER REPLACEMENT PARTS
To have your order filled promptly and correctly, please furnish the following information.
1. MODEL NUMBER 2. REF. NO.
3. PART NO. 4. DESCRIPTION
4-13 PDUC-A637WRF2 U Fan duct 1 AL 4-14 NFANMA002URP0 U Cooling fan 1 AF 4-15 GCOVHA001URP1 U Bottom heater cover 1 AM 4-16 LANGFA155WRP7 U Chassis support 1 AF 4-17 PPACGA001URE0 U Heater packing 1 AD 4-18 LANGQA008URP0 U Grill heater angle 2 AD 4-19 NFANMA001URP0 U Convection fan 1 AD 4-20 PSPAGA001WRE0 U Vibration proof cushion 1 AA 4-21 PCUSUA006URE0 U Air cushion B 1 AA 4-22 PCOVQA002URP0 U Heater cover 1 AD 4-23 PCOVPA308WRE1 U Waveguide cover 1 AE 4-24 PCUSUA015URE0 U Back plate cushion 1 AB 4-25 PPIP-A001UR10 U Pipe 1 AE 4-26 PCOVQA001URP0 U Rear heat cover 1 AP 4-27 PDUC-A606WRF1 U Air intake duct 1 AK 4-28 PDUC-A008URP0 U Exhaust duct 1 AK 4-29 PSKR-A308WRF0 U Rear barrier 1 AH 4-30 PDUC-A003URP0 U Convection duct 1 AL 4-31 PCUSUA012URE0 U Air defect cushion 1 AB 4-32 LANGQA004URP0 U Convection air angle 2 AN
DOOR PARTS
5- 1 DDORFA766WRK0 U Door panel assembly 1 BE 5- 2 GWAKPA103URR0 U Door frame 1 AU 5- 3 LSTPPA017URF0 U Latch head 1 AG 5- 4 LHLD-A012URF0 U Glass holder 1 AB 5- 5 MSPRTA197WREZ U Latch spring 1 AC 5- 6 PGLSPA027URE0 U Front door glass 1 AN 5- 7 JHNDPA012URT0 U Door handle A 1 AK 5- 8 JHNDPA013URT0 U Door handle B 1 AR 5- 9 XETSD40P30000 U Screw : 4mm x 30mm 2 AA 5-10 XEBSD30P08000 U Screw : 3mm x 8mm 3 AA 5-11 XEBSD30P06000 U Screw : 3mm x 6mm 4 AA 5-12 GCOVHA365WRF3 U Choke cover 1 AM
MISCELLANEOUS
6- 1 FAMI-A072WRK2 U High rack 1 AT 6- 2 FAMI-A095WRK1 U Low rack 1 AR 6- 3 LHLDKA008WRF1 U P-clip 1 AA 6- 4 CTNT-A005URK0 U Turntable tray 1 AY 6- 5 FW-VZA061URE1 U Stop switch harness 1 AE 6- 6 TCAUHA001WRR1 U Caution label 1 AC 6- 7 QW-QZA210WRE1 U High voltage wire B 1 AD 6- 8 FW-VZA098URE0 U Main harness 1 AX 6- 9 TINS-A286URR0 U Quick start guide 1 AD 6-10 TINS-A285URR0 U Operation manual 1 AS
SCREWS,NUTS AND WASHERS
7- 1 XHPSD40P08K00 U Screw: 4mm x 8mm 1 AA 7- 2 LX-NZ0061WRE0 J M4 Flange nut 4 AA 7- 3 XWWSD50-06000 J Washer: 5mm x 0.6mm 1 AA 7- 4 XOTSE40P10000 J Screw: 4mm x 10mm 4 AA 7- 5 XHPSD40P06000 J Screw: 4mm x 6mm 3 AA 7- 6 XHTSD40P08RV0 J Screw: 4mm x 8mm 6 AA 7- 7 XOTWW40P06000 J Screw: 4mm x 6mm 10 AA 7- 8 XBTSD40P05000 U Screw: 4mm x 5mm 2 AA 7- 9 XNEUW40-32000 J Nut: 4mm x 3.2mm 1 AA 7-10 XOTSD40P12RV0 J Screw: 4mm x 12mm 2 AA 7-11 XRESE40-06000 U Ring 1 AA 7-12 XWHUW40-08000 U Washer: 4mm x 0.8mm 1 AA 7-13 XWSUW40-10000 U Washer: 4mm x 1.0mm 1 AA 7-14 XEPSD40P25000 J Screw: 4mm x 25mm 2 AA 7-15 XBPWW30P05K00 J Screw: 3mm x 5mm 2 AA 7-16 XWHUW50-08000 J Washer: 5mm x 0.8mm 1 AA 7-17 XEBSD30P06000 U Screw: 3mm x 6mm 3 AA 7-18 LX-CZA001URE0 U Special screw 24 AA 7-19 XFPSD50P10KS0 U Screw: 5mm x 10mm 2 AB 7-20 LX-EZA045WRE0 J Special screw (TTM cover mounting screw) 1 AA
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R-895M - 2
SERVICE MANUAL
MICROWAVE OVEN WITH GRILL AND CONVECTION
R-895(AL)M
GENERAL IMPORTANT INFORMATION
This Manual has been prepared to provide Sharp Corp. Service engineers with Operation and Service Information.
It is recommended that service engineers carefully study the entire text of this manual, so they will be qualified to render satisfactory customer service.
WARNING
Never operate the oven until the following points are ensured. (A) The door is tightly closed. (B) The door brackets and hinges are not defective. (C) The door packing is not damaged. (D) The door is not deformed or warped. (E) There is not any other visible damage with the oven.
Servicing and repair work must be carried out only by trained service engineers.
All the parts marked “*” on parts list are used at voltages more than 250V.
Removal of the outer wrap gives access to potentials above 250V.
All the parts marked “” on parts list may cause undue microwave exposure, by themselves, or when they are damaged, loosened or removed.
Never operate the Grill and/ or Bottom heater with the oven outer cabinet removed. (Because air flow is eliminated, and the excess heat generated on adjacent components). It can cause permanent damage or a fire.
SHARP CORPORATION
OSAKA, JAPAN
WARNING
MICROWAVE RADIATION
Personnel should not be exposed to the microwave energy which may radiate from the magnetron or other microwave generating devices if it is improperly used or connected. All input and output microwave connections, waveguides, flanges and gaskets must be secured. Never operate the device without a microwave energy absorbing load attached. Never look into an open waveguide or antenna while the device is energized.
®
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R-895M - 3
REMEMBER TO CHECK 3D
1) Disconnect the supply.
2) Door opened, and wedged open.
3) Discharge high voltage capacitor.
WARNING: AGAINST THE CHARGE OF THE HIGH-
VOLTAGE CAPACITOR
The high-voltage capacitor remains charged about 60 sec­onds after the oven has been switched off. Wait for 60 seconds and then short-circuit the connection of the high­voltage capacitor (that is, of the connecting lead of the high­voltage rectifier) against the chassis with the use of an insulated screwdriver.
Sharp recommend that wherever possible fault-finding is carried out with the supply disconnected. It may in, some cases, be necessary to connect the supply after the outer case has been removed, in this event carry out
3D checks and then disconnect the leads to the primary of the High voltage transformer. Ensure that these leads remain isolated from other components and the oven chassis. (Use insulation tape if necessary.) When the testing is completed carry out
3D checks and reconnect the leads to the primary of the High voltage transformer.
SERVICING
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts will result in electrocution. High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier assembly, High voltage harness.
REMEMBER TO CHECK 4R
1) Reconnect all leads removed from components during testing.
2) Replace the outer case (cabinet).
3) Reconnect the supply.
4) Run the oven. Check all functions.
Microwave ovens should not be run empty. To test for the presence of microwave energy within a cavity, place a cup of cold water on the oven turntable, close the door and set the power to HIGH and set the microwave timer for two (2) minutes. When the two minutes has elapsed (timer at zero) carefully check that the water is now hot. If the water remains cold carry out
3D checks and re-examine the connections to the compo-
nent being tested.
When all service work is completed, and the oven is fully assembled, the microwave power output should be checked and a microwave leakage test should be carried out.
Page 9
R-895M - 4
PRODUCT DESCRIPTION
SPECIFICATION
ITEM DESCRIPTION
Power Requirements 230 - 240 Volts / 50 Hertz / Single phase, 3 wire earthed
Power Consumption Microwave cooking 1.50 kW Approx. 6.5 A
Convection cooking 1.91 kW Approx. 8.0 A
Top Grill mode ...................... 1.25 kW Approx. 5.2 A
Grill cooking Bottom Grill mode ................. 0.70 kW Approx. 2.9 A
Top and Bottom mode ......... 1.90 kW Approx. 7.9 A
Micro and Top Grill ............... 2.70 kW Approx. 11.5 A
Dual cooking Micro and Bottom Grill .......... 2.15 kW Approx. 9.2 A
Micro and Convection ........... 2.16 kW Approx. 9.3 A
Power Output
900 W nominal of RF microwave energy (measured by method of IEC 60705) Operating fequency 2450 MHz
Top Grill heating element Power Output
1200 W
Bottom heating element Power Output
650 W Case Dimensions Width 520 mm Height 309 mm (including foot) Depth 482 mm Cooking Cavity Dimensions Width 353 mm Height 207 mm Depth 357 mm Turntable diameter 325 mm Control Complement Touch Control System
Clock (1:00 - 12:59) / Timer (0 - 99 minutes 90 sec.)
Microwave Power for Variable Cooking
Repetition Rate;
100 (HIGH) ....................... Full power throughout the cooking time
70 (MEDIUM HIGH) ......................... approx. 70% of FULL Power
50 (MEDIUM) ................................... approx. 50% of FULL Power
30 (MEDIUM LOW).......................... approx. 30% of FULL Power
10 (LOW) ......................................... approx. 10% of FULL Power
Convection temperature control range:
250˚C, 230˚C, 220˚C, 200˚C, 180˚C, 160˚C, 130˚C, 100˚C, 70˚C and 40˚C
TIME keys, BREAKFAST key, PIZZA key,
EXPRESS COOK keys
EXPRESS
DEFROST keys, MEAL IN ONE keys
POWER LEVEL key, GRILL key, DUAL CONV./GRILL key
CONV. (˚C) key, LESS/MORE keys, WEIGHT keys
INFO key, STOP/CLEAR key, START/AUTO MINUTE key
KITCHEN TIMER/CLOCK SET key
Net Weight Approx. 19 kg
GENERAL INFORMATION
WARNING
THIS APPLIANCE MUST BE EARTHED
IMPORTANT
THE WIRES IN THIS MAINS LEAD ARE COLOURED IN ACCORDANCE WITH THE FOLLOWING CODE:
GREEN-AND-YELLOW : EARTH BLUE : NEUTRAL BROWN : LIVE
As part of our policy of continuous improvement, we reserve the right to alter design and specifications without notice
Page 10
R-895M - 5
APPEARANCE VIEW
OVEN
1. Control panel
2. Oven lamp
3. Waveguide cover
4. Bottom grill heating ele­ment (Bottom Grill)
5. Turntable motor shaft
6. Oven cavity
7. Door seals and sealing surfaces
8. Door latches
9. Door opening handle
10.Top grill heating element (Top Grill)
11.Ventilation openings
12.Outer cabinet
13.Powercord
14.Turntable tray
15.High rack
16.Low rack
CONTROL PANEL
14
1 2
9
3678
5 4
10
11
13
12
16 15
KG
COOK
DEFROST
AUTO
%
nfo
AUTO indicator
DEFROST indicator
TOP GRILL indicator.
BOTTOM GRILL indicator
CONVECTION indicator.
COOK indicator
MICROWAVE indicator.
WEIGHT indicators.
LESS/MORE indicators.
DIGITAL DISPLAY
INFO indicator
MICROWAVE POWER  LEVEL indicator.
DIGITAL DISPLAY
TIME keys
PIZZA key
EXPRESS COOK keys
EXPRESS DEFROST keys
MEAL IN ONE keys
LESS/MORE keys
INFO key
START AUTO MINUTE key
DUAL CONV./GRILL key
CONV. (˚C) key
BREAKFAST key
POWER LEVEL key
WEIGHT keys
KITCHEN TIMER/CLOCK SET key
STOP/CLEAR key
GRILL key
NOTE: If the clock has been set, some one-touch cooking features such as "AUTO MINUTE" are disabled after three
minutes when the oven is not used. These features are automatically enabled when the door is opened and closed or the STOP/CLEAR key is pressed.
Page 11
R-895M - 6
OPERATION SEQUENCE
OFF CONDITION
Closing the door activates the monitored latch switch and the stop switch.
IMPORTANT: When the oven door is closed, the contacts COM-NC of the monitor switch must be open. When the micro­wave oven is plugged in a wall outlet (230 - 240V / 50Hz), the line voltage is supplied to the noise filter.
Figure O-1 on page 31
1. The control unit is not energized. The display shows nothing (Fig. O-1 (a)).
2. Open the door. The contacts (COM-NC) of the moni­tored latch switch are closed and the control unit is energized. Then contacts of relays RY1 and RY5 are closed, and the oven lamp will light and the display will show "ENERGY SAVE MODE TO CANCEL ENERGY SAVE MODE SET THE CLOCK" (Fig. O-1(b)).
3. Close the door. The contacts (COM-NC) of the moni­tored latch switch are opened and the contacts of relay RY1 are opened and the oven lamp will be turned off. The display will show " . 0". (Fig. O-1(c)).
NOTE: Energy save mode
1. If the oven has not been used for more than 3 minutes, the contacts of the relay RY5 will be opened and the control unit will not be energized. Open and close the door, the control unit will resume.
2. If the clock is set, this energy save mode does not work.
MICROWAVE COOKING CONDITION
HIGH COOKING
Enter a desired cooking time by touching the TIME keys and start the oven by touching START key.
Function sequence Figure O-2 on page 32
CONNECTED COMPONENTS RELAY Oven lamp, Turntable motor RY1 High voltage transformer RY2 Fan motor RY6
1. The line voltage is supplied to the primary winding of the high voltage transformer. The voltage is converted to about 3.3 volts A.C. output on the filament winding and high voltage of approximately 2000 volts A.C. on the secondary winding.
2. The filament winding voltage (3.3 volts) heats the magnetron filament and the high voltage (2000 volts) is sent to the voltage doubling circuit, where it is doubled to negative voltage of approximately 4000 volts D.C..
3. The 2450 MHz microwave energy produced in the magnetron generates a wavelength of 12.24 cm. This energy is channelled through the waveguide (trans­port channel) into the oven cavity, where the food is placed to be cooked.
4. When the cooking time is up, a signal tone is heard and the relays RY1 + RY2 + RY6 go back to their home position. The circuits to the oven lamp, high voltage transformer, fan motor and turntable motor are cut off.
5. When the oven door is opened during a cooking cycle, the switches come to the following condition.
Switch Contact Condition
During Oven Door Cooking Open(No cooking)
COM-NO Closed Opened
Monitored latch switch
COM-NC Opened Closed
Stop switch
COM-NO Closed Opened COM-NO Closed Opened
Monitor Switch
COM-NC Opened Closed
The circuit to the high voltage transformer is cut off when the contacts of relay RY2, and the contacts (COM-NO) of the monitored latch switch and monitor switch are made open. The circuit to the fan motor is cut off when the relay RY6 is made open. The circuit to the turntable motor is cut off when the contacts (
COM-NO) of the monitored latch
switch are made open. The relay
RY2 and RY6 are made open when the door is opened. The oven lamp remains on even if the oven door is opened after the cooking cycle has been interrupted, because the relay RY1 stays closed. Shown in the display is remaining time.
6. MONITOR SWITCH CIRCUIT
The monitor switch is mechanically controlled by the oven door, and monitors the operation of the moni­tored latch switch.
6-1. When the oven door is opened during or after the
cycle of a cooking program, the monitored latch switch and stop switch must open their contacts (COM-NO) first. After that the contacts (COM-NC) of the monitor switch and monitored latchcan be closed.
6-2. When the oven door is closed, the contacts (COM-
NC) of the monitor switch SW3 must be opened and the contacts (COM-NO) of monitor switch must be closed. After that the contacts (COM-NO) of the monitored latch switch and the stop switch are made closed,
and
the contacts (COM-NC) of the monitored
latch switch are made open
.
6-3. When the oven door is opened and the contacts
(COM-NO) of the monitored latch switch remain closed, the fuse F8A will blow. Because the relay RY1 and monitor switch are closed and a short circuit is caused.
MEDIUM HIGH, MEDIUM, MEDIUM LOW, LOW COOKING
When the microwave oven is preset for variable cooking power, the line voltage is supplied to the high voltage transformer intermittently within a 32-second time base through the relay contact which is coupled with the cur­rent-limiting relay RY2. The following levels of microwave power are given.
Note: The On/Off time ratio does not exactly correspond
to the percentage of microwave power, because approx. 3 seconds are needed for heating up the magnetron filament.
GRILL COOKING CONDITION
TOP GRILL (Figure O-3a)
In this condition the food is cooked by the top grill heating element . Programme the desired cooking time by touch­ing the TIME keys and touh the GRILL key once. When the STARTkey is touched, the following operations occur:
1. The numbers on the digital readout start the count
down to zero.
2. The oven lamp, cooling fan motor and turntable motor
are energized.
900W (HIGH)
32 sec. ON
630W
MEDIUM 
HIGH
Approx. 70%
100%
24 sec. ON 8 sec. OFF
14 sec. OFF
20 sec. OFF
26 sec. OFF
450W (MEDIUM) Approx. 50%
18 sec. ON
270W
MEDIUM 
LOW
Approx. 30%
12 sec. ON
90W (LOW) Approx. 10%
6 sec. ON
Page 12
R-895M - 7
3. The relay RY3 is energized and the main supply voltage is applied to the top grill heating element .
4. Now, the food is cooked by the top grill heating ele­ment.
BOTTOM GRILL (Figure O-3b)
In this condition the food is cooked by bottom grill heating element energy. Programme the desired cooking time by touching the TIME keys and touch the GRILL key twice. When the STARTkey is touched, the following operations occur:
1. The numbers on the digital readout start the count down to zero.
2. The oven lamp, cooling fan motor and turntable motor are energized.
3. The relay RY4 is energized and the main supply voltage is applied to the bottom grill heating element .
4. Now, the food is cooked by the bottom grill heating element .
TOP AND BOTTOM GRILL (Figure O-3c)
In this condition the food is cooked by top and bottom grill heating elements energy. Programme the desired cook­ing time by touching the TIME keys and touch the GRILL key three times. When the STARTkey is touched, the following operations occur:
1. The numbers on the digital readout start the count down to zero.
2. The oven lamp, cooling fan motor and turntable motor are energized.
3. The relay RY4 is energized and the main supply voltage is applied to the bottom grill heating element.
4. The relay RY3 is energized and the main supply voltage is applied to the top grill heating element.
5. Now, the food is cooked by the top and bottom grill heating elements.
CONVECTION COOKING CONDITION
PRE-HEATING (Figure O-4)
Programme the desired convection temperature by touch­ing CONVECTION TEMPERATURE key. When the STARTkey is touched, the following operations occur:
1. The coil shut-off relays RY1 and RY6 are energized, the oven lamp, cooling fan motor and turntable motor are turned on.
2. The coil shut-off relays RY3 and RY4 are energized by control unit and the main supply voltage is added to the top and bottom heating elements.
3. When the oven temperature reaches the selected pre­heat temperature, the following operations occur:
3-1. The coil shut-off relays RY3 and RY4 are energized
by control unit temperature circuit and thermistor, opening the circuit to the top and bottom grill heating elements.
3-2. The oven will continue to function for 30 minutes,
turning the top and bottom heating elements on and off, as needed to maintain the selected pre-heat temperature. The oven will shut-down completely after 30 minutes.
CONVECTION COOKING (Figure O-4)
When the pre-heat temperature is reached, a beep signal will sound indicating that the holding temperature has been reached in the oven cavity. Open the door and place the food to be cooked in the oven. Program desired cooking time by touching the TIME keys and program
convection temperature by touching the CONVECTION TEMPERATURE key . When the START key is touched, the following operations occur:
1. The numbers on the digital readout start the count down to zero.
2. The oven lamp, cooling fan motor, turntable motor and convection motor are energized.
NOTE: When the convection temperature 40˚C is se-
lected, the convection motor is not energized.
3. The relays RY3 and RY4 are energized (if the cavity temperature is lower than selected temperature) and the main supply voltage is applied to the top and bottom heating elements to return to the selected cooking temperature.
4.
Upon completion of the cooking time, the audible sig­nal will sound, and the oven lamp, turntable motor, cooling fan motor, convection motor, top and bottom heating elements are de-energized. At the end of convection cycle, if the cavity air temperature rises above 120˚C, the circuit to the relay RY6 will be main­tained (by the thermistor circuit) to continue operation of the cooling fan motor until temperature drops below 105˚C, at that time the relay RY6 will be de-energized, turning off the fan motor.
DUAL COOKING CONDITION
MICROWAVE AND CONVECTION (Figure O-5a)
Programme the desired cooking time by touching the TIME keys. Touch the DUAL CONVECTION/GRILL key once. Select the microwave power level by touching the MICROWAVE POWER LEVEL key. And select the con­vection temperature by touching the CONVECTION TEM­PERATURE key. When the STARTkey is touched, the following operations occur:
1. The numbers on the digital readout start the count down to zero.
2. The oven lamp, cooling fan motor, turntable motor and convection motor are energized.
3. The relay RY3 will be energized and the main supply voltage is applied to the top grill heatier.
4. The relay RY4 is energized (if the cavity temperature is lower than selected temperature) and the main supply voltage is applied to the bottom heating elementer.
5. The relay RY2 is energized and the microwave energy is generated by magnetron.
6. Now, the food is cooked by microwave and convection energy simultaneously.
MICROWAVE AND TOP GRILL (Figure O-5b)
Programme the desired cooking time by touching the TIME keys. Touch the DUAL CONVECTION/GRILL key twice. Select the microwave power level by touching the MICROWAVE POWER LEVEL key. When the STARTkey is touched, the following operations occur:
1. The numbers on the digital readout start the count down to zero.
2. The oven lamp, cooling fan motor and turntable motor are energized.
3. The relay RY3 is energized and the main supply voltage is applied to the top grill heating element.
4. The relay RY2 is energized and the microwave energy is generated by magnetron.
5. Now, the food is cooked by microwave and top grill simultaneously.
OPERATION SEQUENCE
Page 13
R-895M - 8
MICROWAVE AND BOTTOM GRILL (Figure O-5c)
Programme the desired cooking time by touching the TIME keys. Touch the DUAL CONVECTION/GRILL three times. Select the microwave power level by touching the MICROWAVE POWER LEVEL key. When the STARTkey is touched, the following operations occur:
1. The numbers on the digital readout start the count down to zero.
2. The oven lamp, cooling fan motor and turntable motor are energized.
3. The relay RY4 is energized and the main supply voltage is applied to the bottom grill heating element.
4. The relay RY2 is energized and the microwave energy is generated by magnetron.
5. Now, the food is cooked by microwave and bottom grill simultaneously.
ON/OFF TIME RATIO
In grill cooking, convection cooking or dual cooking, the top heater, bottom heater or magnetron operate whithin a 54 second time base. The following table is the ON / OFF time ratio at each power output of the top heaters, bottom heater or magnetron.
POWER OUTPUT ON TIME OFF TIME
100% 54 sec. 0 sec.
90% 49 sec. 5 sec. 80% 45 sec. 9 sec. 70% 40 sec. 14 sec. 60% 36 sec. 18 sec. 50% 29 sec. 25 sec. 40% 24 sec. 30 sec. 30% 18 sec. 36 sec. 20% 13 sec. 41 sec. 10% 9 sec. 45 sec.
AUTOMATIC COOKING
PIZZA BREAKFAST EXPRESS COOK EXPRESS DEFROST MEAL IN ONE Above functions are automatic cooking. They automati­cally work out the correct cooking mode and cooking time and/or cooking temperature. They will cook according to the special cooking sequence.
AUTO POWER CONTROL OPERATION
The magnetron, top or bottom heating elements, the fan motor or the convection motor will operate in accordance with following specification.
The power level is not reduced 1 time cooking. But only in case same menu is repeated within 1min 15sec, the power level of micro and grill is reduced from 100% to 70% in 20mins after starting of last cooking. (Even if the time of the last cooking is longer than 20mins, the power level isn't reduced on the last cooking, and it is reduced from the beginning of the next cooking.) However, in time calculated from the start of the 1st cooking, even if the Cook mode changed, when repetition cooking of the menu with which 100% of top & bottom heaters continues are performed, as shown in the following table, the power down of the cooking of the 2nd henceforth is carried out. (The 1st cooking is not applied)
In case same cooking mode is repeated within 1min 15sec (including stop, end), oven calculates total cooking time and reduce the power level.
1. OUTPUT POWER CONTROL (MANUAL COOK)
OPERATION MODE DEVICE POWER CONTROL
MICROWAVE (100%)
SINGLE OPERATION
Microwave 100% 20min, then 70%
TOP GRILL (100%)
SINGLE OPERATION
Top heater 100% 15min, then 50%
BOTTOM GRILL (100%)
SINGLE OPERATION
Bottom heater 100% 15min, then 50%
TOP(100%)/BOTTOM(100%)
Top heater 100% 6min then 70% and 70% 9min then 50%
DUAL OPERATION Bottom heater 100% 6min then 70% and 70% 9min then 50%
MICRO(100%)/TOP GRILL(100%) Microwave
100% 20min, then 70%
DUAL OPERATION Top heater 100% 15min, then 50%
MICRO(70 - 10%)/TOP GRILL(100%) Microwave
-
DUAL OPERATION Top heater 100% 15min, then 50%
MICRO(100%)/BOTTOM GRILL(100%) Microwave 100% 20min, then 70%
DUAL OPERATION Bottom heater 100% 15min, then 50%
MICRO(70 - 10%)/BOTTOM GRILL(100%) Microwave -
DUAL OPERATION Bottom heater 100% 15min, then 50%
Microwave
Repeat Cook Top heater
Bottom heater
2. OUTPUT POWER CONTROL (AUTO COOK)
Repeat Auto Cook
OPERATION SEQUENCE
Page 14
R-895M - 9
FUNCTION OF IMPORTANT COMPONENTS
3. COOLING FAN OPERATION
OPERATION MODE DEVICE POWER CONTROL
PREHEAT Cooling 60%
CONV. Cooling fan 60% 60 min. then 100%
Others Cooling fan 100%
After cooking Cooling fan
Indication
4. CONVECTION POWER SETTING
PREHEATING
TEMP 250˚C, 230˚C, 220˚C, 200˚C, 180˚C, 160˚C, 130˚C, 100˚C, 70˚C, 40˚C
HEATING
TOP 100%
ELEMENT
BOTTOM 100%
COOLING FAN 60%
CONV. FAN 0%
CONVECTION
TEMP 250˚C 230˚C 220˚C 200˚C 180˚C 160˚C 130˚C 100˚C70˚C40˚C
WITHOUT HEATING
TOP 50% 40% 40% 30% 20% 10% 10% 10% 10% 10%
PREHEATING ELEMENT
BOTTOM 100% 90% 80% 70% 70% 60% 50% 40% 30% 20%
WITH HEATING
TOP 50% 40% 40% 30% 20% 10% 10% 10% 10% 10%
PREHEATING ELEMENT
BOTTOM 90% 70% 60% 50% 50% 50% 50% 40% 30% 20%
COOLING FAN 60% 60min, then 100%
CONV. FAN 100% 0%
DUAL CONVECTION
TEMP 250˚C 230˚C 220˚C 200˚C 180˚C 160˚C 130˚C 100˚C70˚C40˚C
WITHOUT HEATING
TOP 50% 40% 40% 30% 20% 10% 10% 10% 10% 10%
PREHEATING ELEMENT
BOTTOM 100% 90% 80% 70% 70% 60% 50% 40% 30% 20%
WITH HEATING
TOP 50% 40% 40% 30% 20% 10% 10% 10% 10% 10%
PREHEATING ELEMENT
BOTTOM 90% 70% 60% 50% 50% 50% 50% 40% 30% 20%
MICRO 10%,30%,50%
COOLING FAN 100%
CONV. FAN 100% 0%
NOTE The oven temp was checked by the thermometer when each stages are started .
If the oven temp is same or higher than 105˚C, the oven was judged as "with preheating". When the oven temp is lower than 105˚C or the cooling fan stops, the oven was judged as "without
preheating".
The cooling fan continues to rotate when Oven temperature is more than 120˚C. Then, it stops when it is less than 105˚C
NOW COOLING is indicated during the cooling fan movement after operation is finished. (It isn't indicated during a fan movement to stop on the way.)
Latch hook
Door
SW2: Stop switch
Latch Heads
SW3: Monitor switch
SW1:Monitored  latch switch
Tab
The door can be opened by pulling the door handle. When the handle is pulled, the latch head is pulled, the latch head is moved upward, and released from the latch hook now the door can be opened.
MONITORED LATCH SWITCH
1. When the oven door is closed, the contacts (COM-NO) of the switch must be closed. And the contacts (COM­NC) must be opened.
2. When the oven door is opened, the contacts (COM­NO) of the switch must be opened. And the contacts
(COM-NC) must be closed.
OPERATION SEQUENCE
Figure D-1. Door Open Mechanism
Page 15
R-895M - 10
STOP SWITCH
1. When the oven door is closed, the contacts (COM-NO) of the switch must be closed.
2. When the oven door is opened, the contacts (COM­NO) of switch must be opened.
MONITOR SWITCH
The monitor switch is activated (the contacts opened) by the upper latch head on the door while the door is closed. The switch is intended to render the oven inoperative by means of blowing the fuse F8A when the contacts of the monitored latch switch fail to open when the door is opened.
Function
1. When the door is opened, the contacts (COM-NC) of monitor switch close (to the ON condition) due to their being normally closed and contacts (COM-NO) open. At this time the contacts (COM-NO) of monitored latch switch is in the OFF condition (contacts open) due to their being normally open contact switches.
2. As the door goes to a closed position, the monitor switch contacts (COM-NC) are opened and contacts (COM­NO) closed and then contacts (COM-NO) of monitored latch switch and stop switch are closed.(On opening the door, each of these switches operate inversely.)
3. If the door is opened and the monitored latch switch contacts (COM-NO) fail to open, the fuse F8A blows immediately after closing of the monitor switch (COM­NC) contacts.
CAUTION: BEFORE REPLACING A BLOWN FUSE F8A,
TEST THE MONITORED LATCH SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER “TEST PROCEDURE”).
FUSE 15A 250V
If the wire harness or electrical components are short­circuited, this fuse blows to prevent an electric shock or fire hazard.
FUSE F8A 250V
1. If the wire harness or electrical components are short­circuited, this fuse blows to prevent an electric shock or fire hazard.
2. The fuse also blows when the monitored latch switch remains closed with the oven door open and when the monitor switch contact (COM-NC) closes.
3. The fuse also blows when the asymmetric rectifier, H.V. rectifier,.H.V. wire harness, H.V. capacitor, magnetron or secondary winding of high voltage transformer is shorted.
TC TRANSFORMER
T/C transformer converts A.C. line voltage into low voltage to drive the control unit.
THERMAL CUT-OUT 125˚C (MG)
This thermal cut-out protects the magnetron against over­heat. If the temperature goes up higher than 125˚C be­cause the fan motor is interrupted or the ventilation open­ings are blocked, the thermal cut-out will open and line voltage to the high voltage transformer will cut off and operation of the magnetron will be stopped. The defec­tive thermal cut-out must be replaced with a new one.
THERMAL CUT-OUT 145˚C (OVEN)
This thermal cut-out protects against overheat ing /fire inside the oven. The cut-out contacts will open when temperatures exceed 145˚C.When the cut-out cools itself down to the operating temperature of 115˚C, the contacts of the thermal cut-out will close again.
ASYMMETRIC RECTIFIER
The asymmetric rectifier is solid state device that prevents current flow is both directions. And it prevents the tem­perature rise of the high voltage transformer by blowing the fuseF8A when the high voltage rectifier is shorted.
The rated peak reverse voltage of D1 of the asymmetric rectifier is 6 KV. The rated peak reverse voltage of D2 of the asymmetric rectifier is 1.7 KV. D1 and D2 of the asymmetric rectifier or high voltage rectifier are shorted when the each peak reverse voltage goes beyond the each rated peak reverse voltage. (The process of the blowing the fuseF8A.)
D2 D1
ASYMMETRIC RECTIFIER
HIGH VOLTAGE RECTIFIER
A
B
C
1. The high voltage rectifier is shorted by some fault when microwave cooking or dual cooking.
2. The peak reverse voltage of D2 of the rectifier goes beyond the rated peak reverse voltage 1.7 KV in the voltage doubler circuit.
3. D2 of the rectifier is shorted.
4. The large electric currents flow through the high volt­age winding of the high voltage transformer.
5. The large electric currents beyond 8A flow through the primary winding of the high voltage transformer.
6. The fuse F8A blows by the large electric currents.
7. The power supplying to the high voltage transformer is cut off.
NOISE FILTER
The noise filter assembly prevents radio frequency inter­ference that might flow back in the power circuit.
TURNTABLE MOTOR
The turntable motor rotates the turntable.
FAN MOTOR
The fan motor drives a blade which draws external cool air. This cool air is directed through the air vanes surrounding the magnetron and cools the magnetron. This air is chan­nelled through the oven cavity to remove steam and vapours given off from heating food. It is then exhausted through the exhausting air vents of the oven cavity.
CONVECTION MOTOR
The convection motor drives the convection fan and provide the heated air.
TOP GRILL HEATING ELEMENT
The grill heating element is provided to brown the food and is located on the top of the oven cavity.
FUNCTION OF IMPORTANT COMPONENTS
Page 16
R-895M - 11
FUNCTION OF IMPORTANT COMPONENTS
BOTTOM GRILL HEATING ELEMENT
The grill heating element is provided to brown the food and is located at the base of the oven cavity.
CONVECTION COOKING SYSTEM
This oven is designed with a hot air heating system where food is heated be forced circulation of the hot air produced by the grill heaters. The air heated be the grill heating elements is circulated through the convectin passage provided on the outer casing of the oven cavity be means of the convection fan which is driven by the convection motor. It then enters the inside of the oven through the vent holes provided on the back of the oven. Next, the hot air heats the food on the turntable and leaves the oven cavity through the vent in the oven cavity rear wall. In this way, the hot air ciculates inside the oven cavity to raise its temperature and at the same time, comes into contact with the food cooked. When the temperature inside the oven cavity reaches the selected temperature, the heat­ing elements are de-energized. When the temperature inside the oven cavity drops below the selected tempera­ture, the elements are energized again. In thia way, the inside of the oven is maintained at approximately the selected temperature. When the convection time reaches "0", the heating elements are de-energzed and the con­vection fan stops operating and the oven shuts off. At that time if the cavity air temperature has rised above 120
o
C, the fan remains rotating. Automatically the fan motor will shut down at low temperature (less than 105oC).
FIRE SENSING FEATURE
The oven will stop its operation when there is a fire in the oven cavity in microwave cooking condition. LSI measures the voltage across the temperature meas­urement circuit intermittently within 32-seconds time base since the oven is started in microwave cooking condition. The oven will stop its operation when the difference of the voltage is more than 0.781 volts in microwave cooking condition.
1. Within a 32-seconds base, the thermistor is energized for 2 seconds. At that time, the voltage across the temperature measurement circuit is measured.
2. The oven carries out the procedure above again. If the second voltage is 0.781V higher than first voltage, LSI judges it is a fire in the oven cavity and stop the oven.
3. When LSI judges it is a fire in the oven cavity, LSI will switch off the relays to high voltage transformer and fan motor and LSI stops countring down.
OPEN JUDGE BY THERMISTOR
1. If the temperature of the thermistor does not rise to more than 40˚C after 4 minutes and 15 seconds from when the oven is started in oven cooking mode, dual cooking mode or grill (top and bottom) cooking mode, the oven is turned off.
2. When the thermistor or the wire harness to the thermis­tor is opened, the oven is turned off after 4 minutes and 15 seconds because this condition is same as above
Figure D-2. Convection Cooking system
THERMISTOR
SENSING
VOLTAGE
ON
OFF
ON
OFF
30
32 (sec.)
Sensing the voltage across temperature measurement circuit.
Door
Oven Cavity
Grill Heating Element
Bottom Grill  Heating Element
Convection Passage
Cooling Fan
Convection
Motor
Convection
Fan
Turntable
Insulation
Turntable Motor
Page 17
R-895M - 12
Fuse F8A blows when the door is opened.
Home fuse blows when power cord is plugged into wall outlet.
Fuse 15A blows when power cord is plugged into wall outlet.
Nothing appears in display when power cord is plugged into wall outlet
and the door is opened and closed.
Display does not operate properly when STOP/CLEAR key is touched.
Oven lamp does not light when door is opened. (Display operates.)
Oven does not start when the START key is touched. (Display operates.)
Oven lamp does not light and turntable motor does not operate.
Fan motor does not operate. (Oven lamp lights.)
Convection fan motor does not operate. (Oven lamp lights.)
Turntable motor does not operate. (Oven lamp lights.)
Oven or any electrical parts (except fan motor) does not stop when
cooking time is 0 or STOP/CLEAR key is touched.
Oven stops after 4 minutes and 15 seconds since START key is
touched. (Except Microwave mode)
Display operates properly but all electrical parts do not operate.
Oven goes into cook cycle but shuts down before end of cooking cycle.
After cooking, the temperature of oven cavity is higher than 105˚C but
fan motor does not operate.
Oven seems to be operating but little or no heat is produced in oven
load. (Microwave power control is set at HIGH)
Oven does not seem to be operating properly during variable cooking
condition except HIGH cooking condition.
Oven goes into cook cycle but shuts down before end of cooking cycle.
Convection cooking mode does not heat.
Oven seems to be operating but the temperature in the oven cavity is
lower or higher than preset one.
Grill heating element does operate.
Oven goes into cook cycle but shuts down before end of cooking cycle.
Oven seems to be operating but little or no heat is produced in oven
load. (Microwave power does not seem to be generated properly)
Oven seems to be operating but the temperature in the oven cavity is
lower or higher than preset one.
Top and Bottom Grill heating elements do not heat.
Top or Bottom Grill heating element does not heat.
OFF
CONDITION
COOKING
CONDITION
(COMMON MODE)
MICROWAVE
COOKING
CONDITION
GRILL COOKING
CONDITION
CONVECTION
COOKING
CONDITION
DUAL COOKING
CONDITION
(COMMON MODE)
DUAL COOKING
CONDITION
(MICRO./CONV.)
DUAL COOKING
CONDITION
(MICRO./GRILL)
CONDITION
PROBLEM
BLOCKED
COOLING FAN
BLOCKED
CONVECTION FAN NO POWER AT WALL OUTLET HOME FUSE OR BREAKER MIS-ADJUSTMENT OF SWITCHES BLOCKED VENTILATION OPENINGS OPENED WIRE HARNESS SHORTED WIRE HARNESS OVEN LAMP OR SOCKET POWER SUPPLY CORD FOIL PATTERN ON P.W.B. RELAY RY7 RELAY RY6 RELAY RY5 RELAY RY4 RELAY RY3 RELAY RY2 RELAY RY1 KEY UNIT TOUCH CONTROL PANEL TC TRANSFORMER BTTOM GRILL HEATING ELEMENT TOP GRILL HEATING ELEMENT FUSE F8A FUSE 20A NOISE FILTER CONVECTION FAN MOTOR FAN MOTOR TURNTABLE MOTOR THERMAL CUT-OUT 145˚C (OVEN) THERMAL CUT-OUT 125˚C (MG) THERMISTOR MONITOR SWITCH STOP SWITCH MONITORED LATCH SWITCH HIGH VOLTAGE CAPACITOR H.V. HARNESS H.V. RECTIFIER ASSEMBLY HIGH VOLTAGE TRANSFORMER MAGNETRON
A B C D E E E F G G H H H
TEST PROCEDURE
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
I J K L L M N O O O O O O O P Q
TROUBLESHOOTING GUIDE
Page 18
R-895M - 13
A MAGNETRON TEST
CARRY OUT 3D CHECKS.
Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal.
To test for an open circuit filament use an ohmmeter to make a continuity test between the magnetron filament terminals, the meter should show a reading of less than 1 ohm.
To test for short filament to anode condition, connect ohmmeter between one of the filament terminals and the case of the magnetron (ground). This test should be indicated an infinite resistance. If a low or zero resistance reading is obtained then the magnetron should be replaced.
MICROWAVE OUTPUT POWER
The power output of this oven is rated using the method specified by IEC 60705. Full details of how to curry out this procedure can be found in the Sharp Technical Training notes which is available from Sharp Parts Centre (part number SERV-LITMW01).
The IEC-60705 procedure must be carried out using laboratory-type procedures and equip­ment.
These requirements make the procedure unsuitable for routine performance checks.
NOTE: The following test method gives an indication of the output power only, it cannot be used to
establish the actual/rated output power. If the true output power is required, then the IEC705 test method must be used.
Alternative simplified method:
1. Place 2 litres of cold water (between 12°C and 20°C) in a suitable container.
2. Stir the water and measure the temperature in °C. Note temperature as T1.
3. Place the container in the microwave and heat the water for 1 minute and 36 seconds on full power.
NOTE: The operation time of the microwave oven includes "3" sec. (3 sec. is magnetron filament
heat-up time.)
4. When the 1 minute and 36 seconds is completed, remove the container and stir the water. Note temperature as T2.
5. Calculate the output power using the following formula: R.F. Power Output = (T2 - T1) x 90.
NOTE: The result from this test should be within the allowance of 2000cc alternative method.
(±10%).
MICROWAVE LEAKAGE TEST
This oven should be tested for microwave leakage on completion of any repair or adjustment, following the procedure described in the Sharp Technical Training notes (part number SERV-LITMW01). The maximum leakage permitted in BS EN 60335-2-25 is 50W/m2 (equivalent to 5W/m2), however it is not normal to detect any significant leakage, therefore, any leakage which is detected should be investigated.
It is essential that only leakage detectors with current calibration traceable to National Physical Laboratories are used.
Suitable leakage detectors: CELTEC A100
APOLLO X1
NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL WHILE THE OVEN IS IN OPERATION.
PROCEDURE
LETTER
COMPONENT TEST
TEST PROCEDURES
Page 19
R-895M - 14
C HIGH VOLTAGE RECTIFIER TEST
CARRY OUT 3D CHECKS. Isolate the high voltage rectifier assembly from the HV circuit. The high voltage rectifier can be tested using an ohmmeter set to its highest range. Connect the ohmmeter across the terminal B+C of the high voltage rectifier and note the reading obtained. Reverse the meter leads and note this second reading. The normal resistance is infinite in one direction and more than 100 k in the other direction.
CARRY OUT 4R CHECKS.
ASYMMETRIC RECTIFIER TEST
CARRY OUT 3D CHECKS.
Isolate the high voltage rectifier assembly from the HV circuit. The asymmetric rectifier can be tested using an ohmmeter set to its highest range across the terminals A+B of the asymmetric rectifier and note the reading obtained. Reverse the meter leads and note this second reading. If an open circuit is indicated in both directions then the asymmetric rectifier is good. If the asymmetric rectifier is shorted in either direction, then the asymmetric rectifier is probably faulty and must be replaced with high voltage rectifier. When the asymmetric rectifier is defective, check whether magnetron, high voltage rectifier, high voltage wire or filament winding of the high voltage transformer is shorted.
CARRY OUT 4R CHECKS.
NOTE: FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER, THE BATTERIES OF
THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE AT LEAST 6 VOLTS, BECAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE SHOWN IN BOTH DIRECTIONS.
CARRY OUT 3D CHECKS. Disconnect the leads to the primary winding of the high voltage transformer. Disconnect the filament and secondary winding connections from the rest of the HV circuitry. Using an ohmmeter, set on a low range, it is possible to check the continuity of all three winding. The following readings should be obtained:-
a. Primary winding ................................ approximately 1.9
b. Secondary winding .......................... approximately 124
c. Filament winding ......................................... less than 1
If the readings obtained are not stated as above, then the high voltage transformer is probably faulty and should be replaced. CARRY OUT 4R CHECKS.
D2 D1
ASYMMETRIC RECTIFIER
HIGH VOLTAGE RECTIFIER
CARRY OUT 3D CHECKS.
A. Isolate the high voltage capacitor from the circuit. B. Continuity check must be carried out with measuring instrument which is set to the highest
resistance range.
C. A normal capacitor shows continuity for a short time (kick) and then a resistance of about 10M
after it has been charged. D. A short-circuited capacitor shows continuity all the time. E. An open capacitor constantly shows a resistance about 10 Mbecause of its internal 10M
resistance. F. When the internal wire is opened in the high voltage capacitor shows an infinite resistance. G. The resistance across all the terminals and the chassis must be infinite when the capacitor is
normal. If incorrect reading are obtained, the high voltage capacitor must be replaced.
CARRY OUT 4R CHECKS.
D HIGH VOLTAGE CAPACITOR TEST
WARNING: High voltage and large currents are present at the secondary winding and
filament winding of the high voltage transformer. It is very dangerous to work near this part when the oven is on. NEVER make any voltage measurements of the high-voltage circuits, including the magnetron filament.
TEST PROCEDURES
B HIGH VOLTAGE TRANSFORMER TEST
PROCEDURE
LETTER
COMPONENT TEST
Page 20
R-895M - 15
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make a continuity test across the two terminals as described in the below.
Table: Thermal Cut-out Test
Temperature of "ON" Temperature of "OFF" Indication of ohmmeter
Parts Name condition (closed circuit). condition (open circuit). (When room temperature
(˚C) (˚C) is approx. 20˚C.)
Thermal cut-out 125˚C
This is not resetable Above 125˚C Closed circuit
Thermal cut-out 145˚C
Below 115˚C. Above 145˚C Closed circuit
If incorrect readings are obtained, replace the thermal cut-out.
An open circuit thermal cut-out (MG) indicates that the magnetron has overheated, this may be due to resistricted ventilation, cooling fan failure.
An open circuit thermal cut-out (OVEN) indicates that the oven cavity has overheated, this may be due to no load operation,or excessive heat / fire inside the oven.
CARRY OUT 4R CHECKS.
E SWITCH TEST
Table: Terminal Connection of Switch
Plunger Operation COM to NO COM to NC
Released Open circuit Short circuit Depressed Short circuit Open circuit
COM; Common terminal, NO; Normally open terminal NC; Normally close terminal
If incorrect readings are obtained,replace the switch.
CARRY OUT 4R CHECKS.
CARRY OUT
3D CHECKS. Isolate the switch to be tested and using an ohmmeter check between the terminals as described in the following table.
F THERMISTOR TEST
CARRY OUT 3D CHECKS. Disconnect the connector B from CPU unit. Measure the resistance of the thermistor with an ohmmeter. Connect the ohmmeter leads to Pin No's C1 and C3 of the thermistor harness.
Room Temperature Resistance
20˚C - 30˚C Approximately 359.9 k - 152 k
If the meter does not indiicate above resistance, replace the thermistor.
CARRY OUT 4R CHECKS.
PROCEDURE
LETTER
COMPONENT TEST
G THERMAL CUT-OUT TEST
H MOTOR WINDING TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two terminals as described in the table below.
Table: Resistance of Motor
Motors Resistance Fan motor Approximately 293 Turntable motor Approximately 15 k Convection fan motor Approximately 288
TEST PROCEDURES
Page 21
R-895M - 16
PROCEDURE
LETTER
COMPONENT TEST
J BLOWN FUSE 20A
I NOISE FILTER TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of noise filter. Using an ohmmeter, check between the terminals as described in the following table.
CARRY OUT 3D CHECKS.
If the fuse 20A is blown, there is a shorts or grounds in electrical parts or wire harness. Check them and replace the defective parts or repair the wire harness.
CARRY OUT 4R CHECKS.
CAUTION: Only replace fuse
with the correct value replacement.
K BLOWN FUSE F8A
CARRY OUT 3D CHECKS.
1. If the fuse F8A is blown when the door is opened, check the monitored latch switch and monitor switch.
2. If the fuse F8A is blown by incorrect door switching replace the defective switch(es) and the fuse F8A.
3. If the fuse F8A is blown, there could be shorts in the asymmetric rectifier or there is a ground in wire harness. A short in the asymmetric rectifier may be occurred due to short or ground in H.V. rectifier, magnetron, high voltage transformer or H.V. wire. Check them and replace the defective parts or repair the wire harness.
CARRY OUT 4R CHECKS.
CAUTION: Only replace fuse
F8A with the correct value replacement.
L (min) Cx ± 20% Cy ± 20% R1 R2
1.0mH 0.22µF 4700pF 10 M 680k
MEASURING POINTS INDICATION OF OHMMETER
Between N and L Approx. 680 k Between terminal N and WHITE Short circuit Between terminal L and RED Short circuit
If incorrect readings are absorbed, replace the noise filter unit.
CARRY OUT
4R CHECKS.
L GRILL HEATING ELEMENT (TOP) AND BOTTOM HEATING ELEMENTS TEST
CARRY OUT 3D CHECKS.
Before carrying out the following tests make sure the heating element is cool completely.
1. Resistance of heating element. Disconnect the wire leads to the heating element to be tested. Using ohmmeter with low resistance range. Check the resistance across the terminals of the heating element as described in the following table.
F8A
20A
WHT
RED
R1
R2
N
Cx
Cy
L
L
L
Table: Resistance of heating element
Parts name Resistance Grill heating element (top) Approximately 48 Bottom heating element Approximately 92
2. Insulation resistance. Disconnect the wire leads to the heating element to be tested. Check the insulation resistance between the element terminal and cavity using a 500V - 100M insulation tester. The insulation resistance should be more than 10 M in the cold start.
If the results of above test 1 and/or 2 are out of above specifications, the heating element is probably faulty and should be replaced.
CARRY OUT 4R CHECKS.
TEST PROCEDURES
Page 22
R-895M - 17
M TOUCH CONTROL PANEL ASSEMBLY TEST
The control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance can not be performed with only a voltmeter and ohmmeter. In this service manual, the control panel assembly is divided into two units, Control Unit and Key Unit, and also the Control unit is divided into two units, CPU unit and Power unit, and troubleshooting by replacement is described according to the symptoms indicated.
1. Key Unit Note : Check Key unit ribbon connection before replacement. The following symptoms indicate a defective key unit. Replace the key unit. a) When touching the pads, a certain pad produces no signal at all. b) When touching a number pad, two figures or more are displayed. c) When touching the pads, sometimes a pad produces no signal.
2. Control Panel The following symptoms indicate a defective control unit. Before replacing the control unit perform the key unit test (Procedure N) to determine if control unit is faulty.
2-1 In connection with pads
a) When touching the pads, a certain group of pads do not produce a signal. b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some segments do not light up. b) At a certain digit, brightness is low. c) Only one indicator does not light up. d) The corresponding segments of all digits do not light up; or they continue to light up. e) Wrong figure appears. f) A certain group of indicators do not light up. g) The figure of all digits flicker.
2-3 Other possible troubles caused by defective control unit.
a) Buzzer does not sound or continues to sound. b) Clock does not operate properly. c) Cooking is not possible. d) Proper temperature measurement is not obtained.
PROCEDURE
LETTER
COMPONENT TEST
N KEY UNIT TEST
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the ribbon cable is making good contact, verify that the stop switch operates properly; that is the contacts are closed when the door is closed and open when the door is open. If the stop switch is good, disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the stop switch is closed (either close the door or short the stop switch connecter). Use the Key unit matrix indicated on the control panel schematic and place a jumper wire between the pins that correspond to the STOP/CLEAR pad making momentary contact. If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the control unit does not respond, it is a faulty and must be replaced. If a specific pad does not respond, the above method may be used (after clearing the control unit) to determine if the control unit or key pad is at fault. CARRY OUT 4R CHECKS.
G 9
G10
G11
G12
Pie/
Quiche
Ready
Meals
Rice/
Pasta
Italian
Dish
Indian
Dish
Roast
Pork
Chinese
Dish
Crispy
Potatoes
Roast
Beef/ Lamp
Crispy
Crumb
Foods
DUAL
CONV. /
GRILL
Roast
Poultry
POWER
LEVEL
STOP
CLEAR
PIZZADesserts
10sec. 1min. 10min.
GRILL
BREAKFAST
MORE
Chicken
Quarters
Whole
Poultry
CONV
(˚C)
Meat
Joint
G 8 G 7 G 6 G 5 G 4 G 3 G 2 G 1
UPLESS DOWN
info
START
AUTO MINUTE
KITCHEN TIMER
CLOCK SET
TEST PROCEDURES
Page 23
R-895M - 18
PROCEDURE
LETTER
COMPONENT TEST
control unit with an A.C. voltmeter. The meter should indicate 230-240 volts, if not check oven circuit.
Relay Test Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill operation, convection operation or dual operation.
DC. voltage indicated .......... Defective relay.
DC. voltage not indicated .... Check diode which is connected to the relay coil. If diode is good,
control unit is defective.
RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 Approx. 18.0V D.C. Oven lamp / Turntable motor
RY2 Approx. 18.0V D.C. High voltage transformer
RY3 Approx. 24.0V D.C. Grill (Top) heating element
RY4 Approx. 24.0V D.C. Bottom heating element
RY5 Approx. 24.0V D.C. Touch control transformer
RY6 Approx. 24.0V D.C. Fan motor
RY7 Approx. 24.0V D.C. Convection motor
CARRY OUT 4R CHECKS..
P PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN
To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit on the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given below for repair. Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
STEPS OCCURRENCE CAUSE OR CORRECTION
1 The rated AC voltage is not present between Check supply voltage and oven power cord.
Pin Nos. 1 and 3 of the 4-pin connector (E).
2 The rated AC voltage is present at primary Low voltage transformer or secondary circuit defective.
side of low voltage transformer. Check and repair.
3 Only pattern at “a” is broken. *Insert jumper wire J1 and solder.
(CARRY OUT 3D CHECKS BEFORE REPAIR)
4 Pattern at “a” and “b” are broken. *Insert the coil RCILF2003YAZZ between “c” and “d”.
(CARRY OUT 3D CHECKS BEFORE REPAIR)
NOTE: *At the time of these repairs, make a visual
inspection of the varistor for burning dam­age and examine the transformer with tester for the presence of layer short circuit (check primary coil resistance).
If any abnormal condition is detected, re­place the defective parts.
CARRY OUT 4R CHECKS.
CN-A
CN-E
D12
7
(J1)
D13
VRS1
a
cd
b
TEST PROCEDURES
O RELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 1 and 3 of the 4 pin connector (E) on the
Page 24
R-895M - 19
The touch control section consists of the following units as shown in the touch control panel circuit.
(1) Key Unit (2) Control Unit (The Control unit consists of Power unit
and CPU unit.)
The principal functions of these units and signals commu­nicated among them are explained below.
Key Unit
The key unit is composed of a matrix, signals generated in the LSI are sent to the key unit from P40, P41, P72, P73, P74, P75, P76 and P77. When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through P50 - P53 to perform the function that was requested.
Control Unit
Control unit consists of LSI, power source circuit, synchro­nizing signal circuit, reset circuit, buzzer circuit, relay circuit, temperature measurement circuit, indicator circuit and back light circuit.
1) LSI
This LSI controls the temperature measurement sig­nal, key strobe signal, relay driving signal for oven function and indicator signal.
2) Power Source Circuit
This circuit generates voltage necessary in the control unit.
Symbol Voltage Application
VC -5.2V LSI(IC1)
3) Synchronizing Signal Circuit
The power source synchronizing signal is available in order to compose a basic standard time in the clock circuit. It accompanies a very small error because it works on commercial frequency.
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
4) Reset Circuit
A circuit to generate a signal which resets the LSI to the initial state when power is supplied.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit audible sounds (key touch sound and completion sound).
6) Stop Switch
A switch to “tell” the LSI if the door is open or closed.
7) Relay Circuit
To drive the magnetron, grill heating element, bottom heating element, convection motor, fan motor, turnta­ble motor, touch control transformer and light the oven lamp.
8) Back Light Circuit
A circuit to drive the back light (Light emitting diodes LD1 - LD10).
9) Indicator Circuit
This circuit consists 7-digits, 39-segments and 3-com­mon electrodes using a Liquid Crystal Display.
10)Temperature Measurement Circuit : (OVEN THER­MISTOR)
The temperature in the oven cavity is sensed by the thermistor. The variation of resistance according to sensed temperature is detected by the temperature measurement circuit and the result applied to LSI. The LSI uses this information to control the relay and display units.
Page 25
R-895M - 20
8 AN2 IN Input signal which communicates the door open/close information to LSI.
Door closed; “H” level signal. Door opened; “L” level signal.
9 AN1 IN Heating constant compensation terminal. 10 AN0 IN Terminal to change functions to the Models.
11 P57 OUT Timing signal output terminal for temperature measurement(OVEN
THERMISTOR).
“H” level (GND) : Thermistor OPEN timing. “L” level (-5V) : Temperature measuring timing. (Oven cooking)
12 P56 OUT Terminal not used.
13 P55 OUT Timing signal output terminal for temperature measurement(OVEN
THERMISTOR).
“H” level (GND) : Thermistor OPEN timing. “L” level (-5V) : Temperature measuring timing. (Oven cooking)
14 P54 OUT Terminal not used.
15 P53 IN Signal coming from touch key.
When any one of G12 line keys on key matrix is touched, a corresponding signal from P40, P41, P72, P73, P74, P75, P76 and P77 will be input into P53. When no key is touched, the signal is held at “L” level.
16 P52 IN Signal similar to P53.
When any one of G11 line keys on key matrix is touched, a corresponding signal will be input into P52.
17 P51 IN Signal similar to P53.
When any one of G10 line keys on key matrix is touched, a corresponding signal will be input into P51.
18 P50 IN Signal similar to P53.
When any one of G9 line keys on key matrix is touched, a corresponding signal will be input into P50.
19-22 P47-P44 IN/OUT Terminal not used.
23 TOUT OUT Signal to sound buzzer.
A: Tact switch touch sound. B: Completion sound. C: When the temperature of the oven cavity
reaches the preset temperature in the preheating mode, or when the preheating hold time (30 minutes) is elapsed.
24 INT2 IN Signal to synchronized LSI with commercial power source frequency(50Hz).
This is basic timing for time processing of LSI.
25 P41 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50-P53 terminal while one of G8 line key on matrix is touched.
A
B
C
H : GND
L
0.1 sec.
2.0 sec.
1.0 sec.
1.0 sec.
20 msec.
H : GND
L (-5V)
Pin No. Signal I/O Description
DESCRIPTION OF LSI
The I/O signal of the LSI are detailed in the following table.
1C1INTerminal not used.
2 VL1 IN Power source voltage input terminal.
Standard voltage for LCD.
3 AN7 IN Terminal to change the on timing of the cook relay (RY2). 4-5 AN6-AN5 IN Heating constant compensation terminal. 6 AN4 OUT Terminal not used.
7 AN3 IN Temperature measurement input: OVEN THERMISTOR.
By inputting DC voltage corresponding to the temperature detected by the thermistor, this input is converted into the temperature by the A/D converter built into the LSI.
Page 26
R-895M - 21
Pin No. Signal I/O Description
26 P40 OUT
Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50-P53 terminal while one of G7 line key on matrix is touched.
27 P77 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50-P53 terminal while one of G6 line key on matrix is touched.
28 P76 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50-P53 terminal while one of G5 line key on matrix is touched.
29 P75 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50-P53 terminal while one of G4 line key on matrix is touched.
30 P74 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50-P53 terminal while one of G3 line key on matrix is touched.
31 P73 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50-P53 terminal while one of G2 line key on matrix is touched.
32 P72 OUT Key strobe signal.
Signal applied to touch-key section. A pulse signal is input to P50-P53 terminal while one of G1 line key on matrix is touched.
33 P71 IN/OUT Terminal not used. 34 P70 IN Connected to VC.
35 RESET IN Auto clear terminal.
Signal is input to reset the LSI to the initial state when power is applied. Temporarily set to “L” level the moment power is applied, at this time the LSI is reset. Thereafter set at “Hµ…level.
36 XCIN IN Connected to VC.
37 XCOUT OUT Terminal not used. 38 XIN IN Internal clock oscillation frequency input setting.
The internal clock frequency is set by inserting the ceramic filter oscillation circuit with respect to XOUT terminal.
39 XOUT OUT Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
40 VSS IN Power source voltage: -5V.
VC voltage of power source circuit input.
41 P27 OUT Bottom heating element driving signal.
To turn on and off the relay (RY4). “L” level during grill cooking, convection cooking or dual cooking, “H” level otherwise. The heater relay turns on and off within a 54 second time base in accordance with the special program in LSI.
42 P26 OUT Convection motor driving signal.
To turn on and off shut-off relay (RY7). “L” level during convection or dual cooking, “H” level otherwise. (Relay RY7 does not turn on at preheating mode.)
43 P25 OUT Fan motor driving signal.
To turn on and off the fan motor relay (RY6). “L” level during cooking, or for a while after convection or dual cooking. “H” level otherwise.
44 P24 OUT Terminal not used. 45 P23 OUT Touch control transformer driving signal.
To turn on and off the shut off relay (RY5). If the oven has not been used for more than 2 minutes, the relay RY5 will be turned off. The relay RY5 will be turned on when the oven door is opened and closed.
ON
OFF
During
cooking
L
GND
H.
(Grill, Convection, Dual )
ON
OFF
During
cooking
L
GND
H.
( Convection or Dual cooking )
ON
OFF
During cooking, or for a while after convection or dual cooking.
L
GND
H.
The I/O signal of the LSI are detailed in the following table.
DESCRIPTION OF LSI
Page 27
R-895M - 22
46 P22 OUT Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay (RY2). In 100% operation, the signals hold “L” level during microwave cooking and “H” level while not cooking. In other cooking modes (70%, 50%, 30%, 10%) the signal turns to “H” level and “L” level in repetition according to the power level.
47 P21 OUT Grill (TOP) heating element driving signal.
To turn on and off the grill heating element relay (RY3). “L” level during grill cooking, convection cooking or dual cooking. “H” level otherwise. The heater relay turns on and off within a 54 second time base in accordance with the special progrom in LSI.
48 P20 OUT Oven lamp and turntable motor driving signal(Square Waveform : 50Hz).
To turn on and off shut-off relay (RY1). The square waveform voltage is delivered to the relay (RY1) driving circuit.
49-50 P17-P16 OUT Terminal not used.
51-80 SEG39-SEG10 OUT Segment data signal.
Connected to LCD. The relation between signals are as follows:
LSI signal (Pin No.) LCD (Pin No.) LSI signal (Pin No.) LCD (Pin No.) SEG 0 (90)
....................
SEG39 (51) SEG21 (69)
.................
SEG19 (19)
SEG 1 (89)
....................
SEG38 (50) SEG22 (68)
.................
SEG18 (18)
SEG 2 (88)
....................
SEG37 (49) SEG23 (67)
.................
SEG17 (17)
SEG 3 (87)
....................
SEG36 (48) SEG24 (66)
.................
SEG16 (16)
SEG 4 (86)
....................
SEG35 (47) SEG25 (65)
.................
SEG15 (15)
SEG 5 (85)
....................
SEG34 (46) SEG26 (64)
.................
SEG14 (14)
SEG 6 (84)
....................
SEG33 (45) SEG27 (63)
.................
SEG13 (13)
SEG 7 (83)
....................
SEG32 (44) SEG28 (62)
.................
SEG12 (12)
SEG 8 (82)
....................
SEG31 (43) SEG29 (61)
.................
SEG11 (11)
SEG10 (80)
...................
SEG30 (30) SEG30 (60)
.................
SEG10 (10)
SEG11 (79)
...................
SEG29 (29) SEG31 (59)
...................
SEG 9 ( 9)
SEG12 (78)
...................
SEG28 (28) SEG32 (58)
...................
SEG 8 ( 8)
SEG13 (77)
...................
SEG27 (27) SEG33 (57)
...................
SEG 7 ( 7)
SEG14 (76)
...................
SEG26 (26) SEG34 (56)
...................
SEG 6 ( 6)
SEG15 (75)
...................
SEG25 (25) SEG35 (55)
...................
SEG 5 ( 5)
SEG16 (74)
...................
SEG24 (24) SEG36 (54)
...................
SEG 4 ( 4)
SEG17 (73)
...................
SEG23 (23) SEG37 (53)
...................
SEG 3 ( 3)
SEG18 (72)
...................
SEG22 (22) SEG38 (52)
...................
SEG 2 ( 2)
SEG19 (71)
...................
SEG21 (21) SEG39 (51)
...................
SEG 1 ( 1)
SEG20 (70)
...................
SEG20 (20)
81 SEG9 OUT Terminal not used.
82-90 SEG8-SEG0 OUT Segment data signal.
Connected to LCD. Signal is similar to SEG39.
91 VCC IN Connected to GND.
92 VREF IN Connected to GND.
93 AVSS IN Connected to VC.
94 COM3 OUT Terminal not used.
95 COM2 OUT Common data signal: COM3.
Connected to LCD (Pin No. 35).
96 COM1 OUT Common data signal: COM2.
Connected to LCD (Pin No. 34).
97 COM0 OUT Common data signal: COM1.
Connected to LCD (Pin No. 33).
98-99 VL3-VL2 IN Power source voltage input terminal.
Standard voltage for LCD.
100 C2 IN Terminal not used.
Pin No. Signal I/O Description
During cooking
L
H
20 msec.
ON
OFF
During
cooking
L
GND
H.
(Grill, Convection, Dual )
MICRO ON OFF COOK
100% 54 sec. 0 sec.
70% 40 sec. 14 sec. 50% 29 sec. 25 sec. 30% 18 sec. 36 sec. 10% 9 sec. 45 sec.
MICRO ON OFF COOK
100% 32 sec. 0 sec.
70% 24 sec. 8 sec. 50% 18 sec. 14 sec. 30% 12 sec. 20 sec. 10% 6 sec. 26 sec.
ON/OFF time ratio in Micro cooking (a. 32second time base)
ON/OFF time ratio in Micro cooking (a. 54second time base)
The I/O signal of the LSI are detailed in the following table.
DESCRIPTION OF LSI
Page 28
R-895M - 23
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the circuits. When handling these parts, the following precautions should be strictly followed. CMOS LSI have extremely high impedance at its input and output terminals. For this reason, it is easily influenced by the surrounding high voltage power source, static electricity charge in clothes, etc., and sometimes it is not fully protected by the built-in protection circuit. In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap them in aluminium foil. Also wrap PW boards containing them in aluminium foil.
2) When soldering, ground the technician as shown in the figure and use grounded soldering iron and work table.
2. Shapes of Electronic Components
3. Servicing of Touch Control Panel
We describe the procedures to permit servicing of the touch control panel of the microwave oven and the pre­cautions you must take when doing so. To perform the servicing, power to the touch control panel is available either from the power line of the oven itself or from an external power source.
(1) Servicing the touch control panel with power
supply of the oven :
CAUTION: THE HIGH VOLTAGE TRANSFORMER OF THE
MICROWAVE OVEN IS STILL LIVE DURING SERVICING AND PRESENTS A HAZARD .
Therefore, before checking the performance of the touch
control panel,
1) Disconnect the power supply cord, and then remove
outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power
transformer.
5) Ensure that these leads remain isolated from other
components and oven chassis by using insulation tape.
6) After that procedure, re-connect the power supply
cord.
After checking the performance of the touch control
panel,
1) Disconnect the power supply cord.
2) Open the door and block it open.
3) Re-connect the leads to the primary of the power
transformer.
4) Re-install the outer case (cabinet).
SERVICING
5) Re-connect the power supply cord after the outer case is installed.
6) Run the oven and check all functions.
A. On some models, the power supply cord between the
touch control panel and the oven itself is so short that the two can't be separated.
For those models, check and repair all the controls (sensor-related ones included) of the touch control panel while keeping it connected to the oven.
B. On some models, the power supply cord between the
touch control panel and the oven is long enough that they may be separated from each other. For those models, therefore, it is possible to check and repair the controls of the touch control panel while keeping it apart from the oven; in this case you must short both ends of the door sensing switch (on PWB) of the touch control panel with a jumper, which brings about an operational state that is equivalent to the oven door being closed. As for the sensor-related controls of the touch control panel, checking them is possible if the dummy resistor(s) with resistance equal to that of the controls are used.
(2) Servicing the touch control panel with power
supply from an external power source:
Disconnect the touch control panel completely from the oven, and short both ends of the door sensing switch (on PWB) of the touch control panel, which brings about an operational state that is equivalent to the oven door being closed. Connect an external power source to the power input terminal of the touch control panel, then it is possible to check and repair the controls of the touch control panel; it is also possible to check the sensor-related controls of the touch control panel by using the dummy resistor(s).
4. Servicing Tools
Tools required to service the touch control panel assem­bly.
1) Soldering iron: 30W
(It is recommended to use a soldering iron with a grounding terminal.)
2) Oscilloscope: Single beam, frequency range: DC -
10MHz type or more advanced model.
3) Others: Hand tools
5. Other Precautions
1) Before turning on the power source of the control unit,
remove the aluminium foil applied for preventing static electricity.
2) Connect the connector of the key unit to the control
unit being sure that the lead wires are not twisted.
3) After aluminium foil is removed, be careful that abnor-
mal voltage due to static electricity etc. is not applied to the input or output terminals.
4) Attach connectors, electrolytic capacitors, etc. to PWB,
making sure that all connections are tight.
5) Be sure to use specified components where high
precision is required.
E
C
B
approx. 1M ohm
Transistor KRC243M KTA1274
Page 29
R-895M - 24
9. Discharge the H.V. capacitor before carrying out any further work.
10.Do not operate the oven with the outer case removed.
N.B.; Step 1, 2 and 9 form the basis of the 3D checks.
CAUTION: DISCHARGE HIGH VOLTAGE CAPACITOR
BEFORE TOUCHING ANY OVEN COMPO­NENT OR WIRING.
CAUTION: WHEN THE OUTER CASE CABINET IS RE-
INSTALLED, INSTALL IT BEFORE THE BACK PLATE IS INSTALLED, OR THE OUTER CASE CABINET WILL BE DE­FORMED.
WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below
before operating the oven.
1. Disconnect oven from power supply.
2. Visually check the door and cavity face plate for dam­age (dents, cracks, signs of arcing etc.).
Carry out any remedial work that is necessary before operating the oven. Do not operate the oven if any of the following conditions exist;
1. Door does not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal or damaged.
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. There are defective parts in the microwave generating and transmission assembly.
7. There is visible damage to the oven.
Do not operate the oven:
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.
Please refer to ‘OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS’, when carrying out any of the following removal procedures:
WARNING FOR WIRING
OUTER CASE REMOVAL
To remove the outer case proceed as follows.
1. Disconnect oven from power supply.
2. Open the oven door and wedge it open.
3. Remove the two (2) screws holding the back plate to the oven cavity rear plate. Remove the back plate
4. Remove the air duct assembly from the oven cavity rear plate.
5. Remove the air duct assembly
6. Remove the eight (8) screws from rear and along the side edge of case.
7. Slide the entire case back about 3 cm to free it from retaining clips on the cavity face plate.
8. Lift the entire case from the oven.
HIGH VOLTAGE COMPONENTS REMOVAL
(HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY)
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
To prevent an electric shock, take the following measures.
1. Before wiring,
1) Disconnect the power supply.
2) Open the door and wedge the door open.
3) Discharge the high voltage capacitor and wait for 60 seconds.
2. Don't let the wire leads touch to the following parts;
1) High voltage parts: Magnetron, High voltage transformer, High volt­age capacitor and High voltage rectifier assem­bly.
2) Hot parts: Top heating element, Bottom heating element,
Oven lamp, Magnetron, High voltage transformer and Oven cavity.
3) Sharp edge: Bottom plate, Oven cavity, Waveguide flange, Chassis support and other metallic plate.
4) Movable parts (to prevent a fault) Fan blade, Fan motor, Switch, Turntable motor.
3. Do not catch the wire leads in the outer case cabinet.
4. Insert the positive lock connector certainly until its pin is locked. And make sure that the wire leads should not come off even if the wire leads is pulled.
5. To prevent an error function, connect the wire leads correctly, referring to the Pictorial Diagram.
To remove the components, proceed as follows.
1. CARRY OUT 3D CHECKS.
2. Disconnect the filament lead of the high voltage trans­former and the high voltage transformer secondary wire from the high voltage capacitor.
3. Disconnect the high voltage wire B from the magnetron.
4. Remove one (1) screw holding earth side terminal of the high voltage rectifier assembly.
5. Remove one (1) screw holding fan duct to the oven cavity rear plate.
6. Remove one (1) screw holding capacitor holder to the oven cavity rear plate.
7. Release the capacitor holder from the fan duct.
8. Remove the high voltage capacitor from the capacitor holder.
9. Disconnect the high voltage wire B and the high voltage rectifier assembly from the high voltage capacitor.
10.Disconnect the high voltage rectifier assembly from the high voltage wire B.
11.Now, the high voltage rectifier assembly and the high voltage capacitor should be free.
CAUTION: WHEN REPLACING HIGH VOLTAGE
RETIFIER ASSEMBLY, ENSURE THAT THE CATHODE (EARTH) CONNECTION IS SECURELY FIXED TO THE CAPACITOR.
Page 30
R-895M - 25
MAGNETRON REMOVAL
CONTROL PANEL ASSEMBLY REMOVAL
FAN MOTOR REPLACEMENT
HIGH VOLTAGE TRANSFORMER REMOVAL
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
1. CARRY OUT 3D CHECKS.
2. Disconnect the wire leads and the connectors from the control unit.
3. Remove the one (1) screw holding the control panel assembly to the oven cavity front plate.
4. Lift up the control panel assembly and pull it forward. Now the control panel assembly is free.
NOTE:
1. Before attaching a new key unit, wipe off remaining adhesive on the control panel frame surfaces com­pletely with a soft cloth soaked in alcohol.
2. When attaching the key unit to the control panel frame, adjust the upper edge and right edge of the key unit to the correct position of control panel frame.
3. Stick the key unit firmly to the control panel frame by rubbing with soft cloth not to scratch.
REMOVAL
1. CARRY OUT 3D CHECKS.
2. Remove the one
(1) screw
holding the noise filter to the
chassis support.
3. Release the noise filter from the tabs of the fan duct.
4. Remove the one
(1) screw
holding the chassis support
to the oven cavity front flange.
5. Remove one(1) screw holding the chassis support to the magnetron.
6. Remove the chassis support from the oven cavity.
7. Disconnect the wire leads from the fan duct.
8. Remove the
one
(1) screw holding the capacitor holder
to the oven cavity back plate.
9. Release the tabs of the capacitor holder from the fan duct.
10.Remove the
one
(1) screw holding the fan duct to the
oven cavity back plate.
11.Remove the fan duct from the oven.
12.Remove the fan duct from the fan motor shaft accord­ing to the following procedure.
1) Hold the edge of the rotor of the fan motor by using
a pair of groove joint pliers.
CAUTION:
• Make sure that no swarf from the rotor enters the gap between the rotor & startor of the fan motor.
• Avoid touch the coil of the fan motor with the pliers as the coil may become cut or damaged.
• Avoid deforming the bracket whilst using the pliers.
2) Remove the fan blade assembly from the shaft of the fan motor by pulling and rotating the fan blade with your hand.
3) Now, the fan blade is free.
CAUTION:
• Do not reuse the removed fan blade as the
fixing hole may be oversize.
12.Remove the two (2) screws holding the fan motor to the fan duct.
13.Now, the fan motor is free.
INSTALLATION
1. Install the the fan motor to the fan duct with the two (2) screws.
2. Install the fan blade to the fan motor shaft according to the following procedure.
1) Hold the centre of the bracket which supports the
shaft of the fan motor on a flat table.
2) Apply the screw lock tight into the hole (for shaft) of
the fan blade.
3) Install the fan blade to the shaft of fan motor by
pushing the fan blade with a small, light weight, ball peen hammer or rubber mallet.
CAUTION:
• Do not hit the fan blade when installing be­cause the bracket may be deformed.
• Make sure that the fan blade rotates smoothly after installation.
• Make sure that the axis of the shaft is not slanted.
3. Insert the
tabs of
the capacitor holder to the fan duct.
4. Install the fan duct to the oven cavity back plate with the one (1) screw.
5. Install the capacitor holder to the oven cavity back plate with the one (1) screw.
6. Re-install the chassis support to the oven cavity
with the
one (1) screw
.
7. Re-fit the one(1) screw to secure the chassis support to the magnetron.
8. Install the noise filter to the fan duct and
the chassis
support
with the one (1) screw.
9. Re-connect the wire leads to the fan motor.
1. CARRY OUT 3D CHECKS.
2. Disconnect the filament leads of high voltage trans­former from high voltage capacitor and the magnetron.
3. Disconnect the high voltage transformer secondary wire from the high voltage transformer.
4. Disconnect the main wire harness from the high volt­age transformer.
5. Remove the two (2) screws and one (1) washer holding the transformer to the base plate.
7. Remove the transformer.
8. Now the high voltage transformer is free.
1. CARRY OUT 3D CHECKS.
2. Disconnect the H.V. wire B and filament lead of the transformer from the magnetron.
3. Remove the one (1) screw holding the chassis support to the magnetron.
4. Move the air intake duct to left.
5. Carefully remove four (4) screws holding the magnetron to the waveguide. When removing the screws hold the magnetron to prevent it from falling.
6. Remove the magnetron from the waveguide with care so the magnetron antenna is not hit by any metal object around the antenna.
CAUTION: WHEN REPLACING THE MAGNETRON,
BE SURE THE R.F. GASKET IS IN PLACE AND THE MAGNETRON MOUNTING SCREWS ARE TIGHTENED SECURELY.
Page 31
R-895M - 26
Terminal
Push
Pull down
1
2
Lever
Positive lock¤ connector
Cutting pliers
Bridges
Bridges
Turntable motor
cover
Screw;  LX-EZA045WRE0
Turntable motor cover
Base plate
Tabs
Slits
Coil
Gap
Rotor
Bracket
Stator
Groove joint pliers
Shaft
Axis
Stator
Rotor
These are the positions that should be pinched with pliers.
Shaft
Table
Center of bracket
TURNTABLE MOTOR REPLACEMENT
Figure C-1(a). Turntable motor cover removal Figure C-1(b). Turntable motor cover re-install
POSITIVE LOCK® CONNECTOR REMOVAL
1. CARRY OUT 3D CHECKS.
2. Push the lever of positive lock® connector.
3. Pull down on the positive lock® connector.
CAUTION: WHEN YOU (SERVICE ENGINEERS) CON-
NECT THE POSITIVE LOCK® CONNEC­TORS TO THE TERMINALS, CONNECT THE POSITIVE LOCK® SO THAT THE LE­VER FACES YOU.
Figure C-2. Positive lock®connector
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
Removal
2. Remove the turntable from the oven cavity.
3. Turn the oven over.
4. Cut the four (4) bridges holding the turntable motor cover to the base plate with cutting pliers as shown in Figure C-2(a).
CAUTION: DO NOT DROP THE TURNTABLE MOTOR
COVER INTO THE OVEN AFTER CUTTING THE BRIDGES. BECAUSE IT WILL DAM­AGE THE WIRE LEADS OF THE MOTOR AND IT IS DIFFICULT TO REMOVE IT OUT OF THE OVEN.
5. Remove the turntable motor cover from the base plate.
6. Disconnect the wire leads from the turntable motor.
7. Remove the one (1) screw holding the turntable motor to the turntable motor angle.
8. Bend the turntable motor retaining tab back to release
the motor.
9. Remove the turntable motor from the turntable motor angle. Now, the turntable motor is free.
Re-install
1. Remove the any sharp edges on the turntable motor cover and the base plate with the cutting pliers.
2. Re-install turntable motor by locating shaft onto turnta­ble motor shaft to the turntable motor angle with the one (1) screw.
3. Bend the turntable motor retaining tab forward to se­cure the motor.
4. Re-connect the wire leads to the turntable motor.
5. Insert the two (2) tabs of the turntable motor cover into the slits of the base plate as shown in Figure C-2(b).
6. Re-install the turntable motor cover to the base plate with the screw (LX-EZA045WRE0) as shown in Figure C-2(b).
Page 32
R-895M - 27
Power supply cord
Green/ Yellow wire
Brown wire
Oven cavity back plate
Blue wire
Noise filter
Screw
L
TP
F 8 A
TL
RED
20 A
WHT
N
POWER SUPPLY CORD
MOULDING CORD STOPPER
OVEN CAVIT
Y
BACK PLATE
SQUARE HOLE
1. CARRY OUT 3D CHECKS.
2. Remove the two(2)wires leads as Positive lock
®
connector removal above.
3. Lift up the oven lamp from its retaining clips.
4. Now, the oven lamp is free.
Figure C-3. Oven lamp
Removal
1. CARRY OUT 3D CHECKS.
2. Remove the one (1) screw holding the green/yellow wire to the cavity back plate.
3. Disconnect the leads of the power supply cord from the noise filter, referring to the Figure C-4(a).
4. Release the power supply cord from the rear cabinet.
5. Now, the power supply cord is free.
Re-install
1. Insert the moulding cord stopper of power supply cord into the square hole of the cavity backplate, referring to the Figure C-4(b).
2. Install the earth wire lead of power supply cord to the oven cavity with one (1) screw and tight the screw.
3. Connect the brown and blue wire leads of power supply cord to the noise filter correctly, referring to the Pictorial Diagram.
POWER SUPPLY CORD REPLACEMENT
OVEN LAMP SOCKET REMOVAL
BULB
LOCK
TOP HEATING ELEMENT REMOVAL
1. CARRY OUT 3D CHECKS.
2. Remove the two (2) screws holding the two (2) termi­nals of the main wire harness to the top heating element.
3. Remove the two (2) screws holding the two (2) grill heater angles to the top of the oven cavity.
4. Remove the two (2) grill heater angles from the oven cavity.
5. Remove the top heating element from the top of the oven cavity.
6. Now the top heating element is free.
Figure C-4 (a) Replacement of Power Supply Cord Figure C-4(b). Power Supply Cord Replacement
BOTTOM HEATING ELEMENT REMOVAL
MONITORED LATCH SWITCH, MONITOR SWITCH AND STOP SWITCH REMOVAL
1. CARRY OUT 3D CHECKS.
2. Remove the control panel assembly referring to "CON­TROL PANEL ASSEMBLY REMOVAL".
3. Disconnect the leads from all switches.
4. Remove the two (2) screws holding the latch hook to the oven cavity.
5. Remove the latch hook.
6. Remove the switch(es) from the latch hook by pushing the retaining tab backwards slightly and turning the switch(es) on the post.
7. Now the switch(es) is free.
SW2: Stop switch
SW3: Monitor switch
SW1:Monitored  latch switch
Tab
Post
Post
Figure C-5. Switches
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
1. CARRY OUT 3D CHECKS.
2. Remove the turntable motor cover from the base plate, referring to "TURNTABLE MOTOR REPLACEMENT".
3. Disconnect the wire leads from the bottom heating element.
4. Remove the two (2) nuts holding the heater cover and heater packing to the bottom heater.
5. Remove the heater cover and the heater packing from the bottom heating element.
6. Re-move the two(2) nuts holding the bottom heating element to the oven cavity.
7. Remove the bottom heating element from the oven cavity .
Page 33
R-895M - 28
Choke Cover
Putty Knife
Door Frame
Latch hook
Door
SW2: Stop switch
Latch Heads
SW3: Monitor switch
SW1:Monitored  latch switch
Tab
MONITOR
ED LATCH SWITCH, STOP SWITCH AND MONITOR SWITCH ADJUSTMENT
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
DOOR REPLACEMENT
If the monitored latch switch, stop switch and monitor switch do not operate properly due to a mis-adjustment, the following adjustment should be made.
1. CARRY OUT 3D CHECKS.
2. Loosen the two (2) screws holding the latch hook to the oven cavity front flange.
3.
With the door closed, adjust the latch hook by moving it back and forward or up and down. In and out play of the door allowed by the latch hook should be less than
0.5 mm. The horizontal position of the latch hook should be placed where the monitor switch has activated with the door closed. The vertical position of the latch hook should be placed where the monitored latch switch and stop switch have activated with the door closed.
4. Secure the screws with washers firmly.
5.
Make sure that all switches operate. If the latch head has not pushed the plungers of the monitor switch with door closed, adjust the latch hook position. At that time, the latch head should have pushed the plungers of the monitored latch switch and stop switch. If the latch head has not pushed the plungers of the monitored latch switch and stop switch with door closed, loose two (2) screws holding latch hook to oven cavity front flange and adjust the latch hook position.
After adjustment, make sure of following:
1. In and out play of door remains less than 0.5 mm when latched position. First check the latch hook position, pushing and pulling upper portion of the door toward the oven face. Then check the lower latch hook posi­tion, pushing and pulling lower portion of the door toward the oven face. Both results (play of the door)
should be less than 0.5mm.
2. The contacts (COM-NO) of the stop switch and the monitored latch switch open within 1.8mm gap be­tween right side of cavity face plate and door when door is opened.
3. When the door is closed, the contacts (COM-NO) of the stop switch close.
4. When the door is closed the contacts (COM-NC) of the monitor switch and monitored latch switch open. And the contacts (COM-NO) of their switches close.
5. Re-install outer case and check for microwave leakage around the door with an approved microwave survey meter. (Refer to Microwave Measurement Procedure.)
REMOVAL
1. Disconnect the oven from the power supply.
2. Pull open the door slightly.
3. Insert a putty knife (thickness of about 0.5mm) into the gap between the choke cover and door frame as shown in Figure C-7 to free engaging parts.
4. Release choke cover from door panel.
5. Now choke cover is free.
NOTE: When carrying out any repair to the door, do
not bend or warp the slit choke (tabs on the door panel assembly) to prevent microwave leakage.
Figure C-7. Door Disassembly
6. Lift the door upwards.
7. Now, door sub assembly is free from oven cavity.
8. Remove the four (4) screws holding the door panel to the door frame.
9. Now, door panel is free.
10.Slide latch head upward and remove it from door frame with releasing latch spring from door frame and latch head.
11.Now, latch head and latch spring are free.
12.Remove the glass stopper from the door frame.
13.Slide the front door glass leftwards and then slide upwards to release the tabs holding it.
14.Now, the front door glass is free
RE-INSTALL
1. Re-install the front door glass to the door frame as follows. a) Insert the upper edge of the front door glass into the
four (4) tabs of the door frame.
b) Slide the front door glass downwards and insert the
lower edge of the front door glass into the four (4) tabs of the door frame.
c) Slide the front door glass rightwards and insert the
right edge of the front door glass into the three (3) tab of the door frame.
2. Re-install the glass stopper to the door frame.
3. Re-install the latch spring to the latch head. Re-install the latch spring to the door frame. Re-install latch head
Figure C-6 Latch Switches Adjustment
Page 34
R-895M - 29
Pin
PIN
Lower Oven Hinge
Upper Oven Hinge
Lower Oven Hinge
Choke Cover
Slit Choke
Door Panel
Door Sub Assembly
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
to door frame.
4. Re-install door panel to door frame by fitting two (2) tabs of glass stopper to two (2) holes of door panel.
5. Hold the door panel to the door frame with four (4) screws.
6. Located door panel hinge pins into cavity hinge loca­tion hole.
7. Re-install choke cover to door panel by clipping into position.
Note: After any service to the door; (A) Make sure that the monitor switch, monitored
latch switch and stop switch are operating prop­erly. (Refer to chapter "Test Procedures".).
(B) An approved microwave survey meter should be
used to assure compliance with proper micro­wave radiation emission limitation standards. (Refer to Microwave Measurement Procedure.)
After any service, make sure of the following :
1. Door latch heads smoothly catch latch hook through latch holes and that latch head goes through centre of latch hole.
2. Deviation of door alignment from horizontal line of cavity face plate is to be less than 1.0mm.
3. Door is positioned with its face pressed toward cavity face plate.
4. Check for microwave leakage around door with an approved microwave survey meter. (Refer to Micro­wave Measurement Procedure.)
Note: The door on a microwave oven is designed to act
as an electronic seal preventing the leakage of microwave energy from oven cavity during cook cycle. This function does not require that door be air-tight, moisture (condensation)-tight or light­tight. Therefore, occasional appearance of mois­ture, light or sensing of gentle warm air movement around oven door is not abnormal and do not of themselves, indicate a leakage of microwave en­ergy from oven cavity.
Figure C-8. Door Replacement
Page 35
R-895M - 30
MICROWAVE MEASUREMENT
After any repair, the microwave oven must be checked for microwave leakage to ensure continued safe operation. BS EN 60335-2-25 specifies that the maximum permitted leakage with a load of 275 ml is 50 W/m2 (equivalent to 5 mW/cm2) at a distance of 5 cm from the oven.
PREPARATION
The following items are required to carry out this test:-
1. A low form of 600 ml beaker made from an electrically non-conductive material, such as glass or plastic, with an inside diameter of approximately 8.5 cm. This must contain 275 ± 15 ml of water, at an initial temperature of 20 ± 2˚C.
2. A leakage detector which has been calibrated within the preceding 12 months to a stand whose accuracy can be traced to National Physical Laboratory Stand­ards.
Recommended instruments are:
Apollo "XI" Celtec "A100"
Before commencing the test, check that the leakage detector is functioning and adjusted according to the manufacturer's instructions, and any spacers are fitted to ensure that measurement is taken 5cm from the surface of the oven.
PROCEDURE
1. Place the beaker containing the water load in the oven cavity at the centre of the turntable. The placing of this standard load in the oven is important, not only to protect the oven, but also to ensure that any leakage it is not disguised by too large a load absorbing energy.
2. Close the oven door, and with the power level set to FULL, turn the oven ON with the timer set for a few minutes operation. Should the water begin to boil before the test has been completed, it should be replaced.
3. As shown in the diagram below, move the probe slowly (not faster than 2.5 cm/sec.);-
a) around the edge of the door following the gap b) across the face of the door c) across any vents in the oven's sides, rear or top
Microwave leakage measurement at 5 cm distance
SHARP
Whilst the maximum leakage permitted in BS EN 60335-2-25 is 50 W/m2 (equivalent to 5 mW/cm2), it is not normal to detect any significant leakage, and therefore any detected leakage should be investigated.
Dotted line indicates the path taken by the leakage detec­tor.
Page 36
R-895M - 31
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR OPENED.
2. "ENERGY SAVED MODE" APPEARS ON DISPLAY.
Figure O-1(c) Oven Schematic-OFF Condition after the oven door is closed.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. " . O" APPEARS ON DISPLAY.
Figure O-1(b) Oven Schematic-OFF Condition when the oven door is opened.
Note: AC CORD CONNECTION BRN : BROWN BLU : BLUE G-Y : GREEN AND YELLOW STRIPE /15 : SECTIONAL AREA OF 1.5mm2 MIN.
" " Indicates components with potential above 250 V.
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
Note: AC CORD CONNECTION BRN : BROWN BLU : BLUE G-Y : GREEN AND YELLOW STRIPE /15 : SECTIONAL AREA OF 1.5mm
2
MIN.
" " Indicates components with potential
above 250 V.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. PLUGGED IN OVEN.
3. NOTHING APPEARS ON DISPLAY.
Figure O-1(a) Oven Schematic-OFF Condition right after the oven is plugged in.
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
SCHEMATIC DIAGRAMS
Page 37
R-895M - 32
Figure O-3(a) Oven Schematic-Grill cooking Condition (TOP GRILL mode)
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. TOP GRILL MODE SELECTED.
4. STRAT KEY TOUCHED.
Figure O-3(b) Oven Schematic-Grill cooking Condition (BOTTOM GRILL mode)
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. BOTTOM GRILL MODE SELECTED.
4. STRAT KEY TOUCHED.
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
: OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
Figure O-2 Oven Schematic-Microwave cooking Condition
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. STRAT KEY TOUCHED.
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
SCHEMATIC DIAGRAMS
Page 38
R-895M - 33
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. CONVECTION TEMPERATURE SELECTED.
4. STRAT KEY TOUCHED.
Figure O-4 Oven Schematic-Convection Condition
NOTE: The top heating element, bottom heating element, fan motor and convection
motor will be turned on and off according to the temperature.
See "AUTO POWER CONTROL SPEC.
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. TOP & BOTTOM GRILL MODE SELECTED.
4. STRAT KEY TOUCHED.
Figure O-3(c) Oven Schematic-Grill cooking Condition (TOP AND BOTTOM GRILL mode)
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
SCHEMATIC DIAGRAMS
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. DUAL KEY TOUCHED ONCE.
4. MICROWAVE POWER LEVEL ENTERED.
5. CONVECTION TEMPERATURE SELECTED.
6. STRAT KEY TOUCHED.
NOTE: The top heating element, bottom heating element, magnetron, fan motor and
convection motor will be turned on and off according to the temperature or microwave power level. See "AUTO POWER CONTROL SPEC.
Figure O-5(a) Oven Schematic-Dual cooking Condition (Microwave and Convection mode)
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
Page 39
R-895M - 34
Figure O-5(b) Oven Schematic-Dual cooking Condition (Microwave and Top Grill mode)
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. DUAL KEY TOUCHED TWICE.
4. MICROWAVE POWER LEVEL ENTERED.
5. STRAT KEY TOUCHED.
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. COOKING TIME ENTERED.
3. DUAL KEY TOUCHED THREE TIMES.
4. MICROWAVE POWER LEVEL ENTERED.
5. STRAT KEY TOUCHED.
Figure O-5(c) Oven Schematic-Dual cooking Condition (Microwave and Bottom Grill mode)
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
OL
CM
TTM
OVEN LAMP
CONVECTION 
MOTOR
FAN MOTOR
TURNTABLE MOTOR
TOP GRILL HEATING ELEMENT
BOTTOM HEATING ELEMENT
H.V. RECTIFIER
MAGNETRON
HIGH VOLTAGE 
TRANSFORMER
T/C TRANSFORMER
CAPACITOR
1.13 µF
AC2100V
CONTROL UNIT
A9
A7
RY7
RY5
COM.
COM.
COM.
N.O.
N.O.
COM.
N.O.
N.O.
A3
E1 E3
E5 E7
A1
B2
C3
C1
A5
B1
STOP SWITCH
MONITORED LATCH SWITCH
THERMISTOR
MG. THERMAL CUT-OUT
 OVEN THERMAL CUT-OUT
 MONITOR  SWITCH
4700p/ 250V
4700p/ 250V
10M/ 0.5W
NOISE SUPPRESSION COIL
680 k/ 0.5W
0.22µ/250V
FUSE 20A
FUSE F8A
NOISE  FILTER
LN
230 - 240V ~ 50Hz
BRN/15BLU/15
G-Y/15
EARTH
LIVENEUTRAL
NC.
NC.
ASYMMETRIC RECTIFIER
RY6
RY1 RY2 RY3 RY4
FM
SCHEMATIC DIAGRAMS
Page 40
R-895M - 35
Figure S-1. Pictrorial Diagram
PICTORIAL DIAGRAM
WHT
WHT
BLK
WHT
TC2: OVEN THERMAL
CUT-OUT
TC1:
MG. THERMAL
CUT-OUT
OL: OVEN LAMP
ORG
RED
WHT
1 BRN
283 ORG
4
5 GRY
6
7 WHT
9 BLU
COM
GRY
WHT
BLU
GRY
RED
WHT
N.C.
NC
COM
SW2: STOP
SWITCH
NO
COM
GH1: TOP GRILL
HEATING ELEMENT
GH2:BOTTOM
HEATING
ELEMENT
GRY
RED
WHT
BRN
BLU
GRN
GRN
GRN
BLU
TTM:
TURNTABLE
MOTOR
T/C TRANSFORMER
SW3:
MONMITOR
SWITCH
SW1:
MONITORED
LATCH
SWITCH
ORG
ORG
BLU
BRN
BRN
RED
RED
RED
RED
ORG
RED
BLK
BLU
GRY
CN-A
1
CN-B
2
RED
GRN
RED
GRY
GRY
ORG
RED
NOISE FILTER
L
TP
F 8 A
TL
RED
20 A
WHT
N
ORG
ORG
1 BLU
2
3 BRN
4
5 ORG
6
7 RED
FM: FAN
MOTOR
GRY
RED
WHT
HIGH VOLTAGE COMPONENTS
G–Y
POWER SUPPLY
CORD
NEUTRAL
LIVE
EARTH
CN-B
112
2
1
SP1
RY2
RY4
RY3
CONTROL PANEL
CN-A
CN-E
RY5
1
1
7
9
CN-F
CN-E
WH-1
CN-1
IC-1
CN-J
RY1
RY6
RY7
MG:MAGNETRON
H.V.WIRE B
T:
C:
H.V.
CAPACITOR
H.V.
RECTIFIER
ASYMMETRIC
RECTIFIER
HIGH VOLTAGE
TRANSFORMER
RED
BRN
BRN
BRN
WHT
THERMISTOR
1
3
CN-C
2
3
1
BLK
BLK
CN-C
CM: CONVECTION
MOTOR
BLU
BRN
BRN
RED
Page 41
R-895M - 36
Figure S-2. Power Unit Circuit
E 1
WH1-3
WH1-6
WH1-9
WH1-5
WH1-8
WH1-1
WH1-2
WH1-n
WH1-10
WH1-12
WH1-13
WH1-14
WH1-15
WH1-11
E 3
E 5
E 7
T1
AC230-240V 50Hz
FAN MOTOR
OVEN THERMISTOR
GND
GND
R3 510 1w
R6 200 1w
Q2 KTA1274
Q3 KRC243M
R4 510 1w
D11-D14 1N4005E or 1N4004S
RY5
ab
c
d
D11
D12
D13
D14
C1
VRS1
(J1)
(J2)
D5
RY6
D6
RY1
D1
R2
1.5k
ZD2
HZ20-1
RY4
D4
RY3
D3
RY2
D2
10G471K
C3
C2 1000µ/35v
C5
10µ/35v
C4 10µ/35v
R5 3.3k
SP1
VC
BUZZER
VR
INT POWER
CONTROL
STOP SWITCH
NC
BOTTOM HEATING ELEMENT
GRILL HEATING ELEMENT
HIGH VOLTAGE TRANSFORMER
STOP SWITCH
OVEN LAMP TURNTABLE MOTOR
DOOR OPEN
CONTACT
A 1
A 3
A 5
C 3
A 7
N O
N O
N O
N O
COM
COM
COM
COM
B 2
B 1
NOTE 1. NOTE 2.
+
+
+
WH1-7
CONVECTION MOTOR
RY7
D7
A 9
: IF NOT SPECIFIED, 1/4W ± 5% 15P WIRE HARNESS : IF NOT SPECIFIED, 0.1µF / 50V
: IF NOT SPECIFIED, 1SS270A
C 1
WH1-4
POWER UNIT CIRCUIT DIAGRAM
Page 42
R-895M - 37
Figure S-3. CPU Unit Circuit
D-5
D-6
D-10
D-1
D-2
D-4
G 9
G10
G11
G12
D-15
C9
C8
+
+
C10 47µ/16v
C15
1µ/50v
C21 0.1µ/50v
C60 330p/50v
C61 330p/50v
C62 330p/50v
C63 330p/50v
D22
D23
D30
R31 15k
R81 1.5kF
R83 15k
R82 27kF
R16 330
R72 100k
R73 100k
R74 100k
CF1 4.0MHz
Pie/
Quiche
Ready
Meals
Rice/
Pasta
Italian
Dish
Indian
Dish
Roast
Pork
Chinese
Dish
Crispy
Potatoes
Roast
Beef/
Lamp
Crispy
Crumb
Foods
DUAL
CONV. /
GRILL
Roast
Poultry
POWER
LEVEL
STOP
CLEAR
PIZZADesserts
10sec. 1min. 10min.
GRILL
BREAKFAST
MORE
Chicken
Quarters
Whole
Poultry
CONV
(˚C)
Meat
Joint
CN-G
(B)
(A)
(D)(F)
(C)
(E)(G)
R75 100k
C13
0.1µ
/50v
C30C80
C12
0.1µ
/50v
C14
Q11
KRA101S
LD1 LD2 LD3 LD4 LD5
LD10 LD9 LD8 LD7 LD6
Q10
2SA1037AK
GND
51pin
1pin
Q40
KRA101S
Q28
KRA101S
Q24
KRA101S
IC1
LIQUID CRYSTAL DISPLAY
OVEN LAMP
TURNTABLE
MOTOR
OVEN
THERMISTOR
CONVECTION
MOTOR
POWER
BUZZER
VR
VC
GND
INT
TOP GRILL
HEATING
ELEMENT
BOTTOM
HEATING
ELEMENT
NOTE
: IF NOT SPECIFIED, 1/16W ± 5%
: IF NOT SPECIFIED, 1SS355
: IF NOT SPECIFIED, 0.01µF / 50V
HIGH
VOLTAGE
TRANSFORMER
STOP
SWITCHNC
Q23
KRA101S
Q22
KRA105S
Q21
KRA105S
Q20
KRA105S
(D:P23)
(F:P26)
(A:P20)
(B:P21)
(G:P27)
(C:P22)
R6 330
R7
330
Q2
2SA1037AK
R4 22
R68 15k
R56
1M
R69 15k
R70 15k
R71 15k
D6 D5
R5 4.7k
R30
4.7k
R15
4.7k
ZD10
UDZ4.3B
(J18)
(J21) 4.7k
(J20) 4.7k
(J19)
(J13) 4.7k (J10)
(J14) 4.7k
(J15) 4.7k
(J11)
(J12)
R10 1k
R12 15k R13 15k R14 15k
R11 4.7k
D-13
D-12
D-14
D-11
D-7
D-9
SEG10C1 1
5
10
15
20
25
30 51
55
60
65
70
75
80
31
35
40
45
50 81
85
90
95
VL1
AN7
AN6
AN5
AN4
AN3
AN2
AN1
AN0
P57
P56
P55
P54
P53
P52
P51
P50
P47
P46
P45
P44
TOUT
INT2
P41
P40
P77
P76
P75
P74
SEG11
SEG12
SEG13
SEG14
SEG15
SEG39
SEG38
SEG37
SEG36
SEG35
SEG34
SEG33
SEG32
SEG31
NCNCNCNCNCNCNC
COM3
COM2
COM1
NC
NC
SEG30
SEG29
SEG28
SEG27
SEG26
SEG25
SEG24
SEG23
SEG22
SEG21
SEG20
SEG19
SEG18
SEG17
SEG16
SEG15
SEG14
SEG13
SEG12
SEG11
SEG10
SEG9
SEG8
SEG7
SEG6
SEG5
SEG4
SEG3
SEG2
SEG1
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2019181716151413121110
987654321
SEG16
SEG17
SEG18
SEG19
SEG20
SEG21
SEG22
SEG23
SEG24
SEG25
SEG26
SEG27
SEG28
SEG29
SEG30
SEG31
SEG32
SEG33
SEG34
SEG35
SEG36
SEG37
SEG38
SEG39
P73 C2
VL2
VL3
COM0
COM1
COM2
COM3
AVSS
VREF
VCC
SEG0
SEG1
SEG2
SEG3
SEG4
SEG5
SEG6
SEG7
SEG8
SEG9
P72
P71
INT0
RESET
XCIN
XCOUT
XIN
XOUT
VSS
P27
P26
P25
P24
P23
P22
P21
P20
P17
P16
nfo
LBSKGOZ
PCS%˚C
COOK SENSOR DEFROST AUTO
C11 0.1µ/50v
R19 330
Q25
KRA101S
FAN MOTOR
(E:P25)
D-8
R18 330
R17 330
D-3
C50 4.7k
G 8 G 7 G 6 G 5 G 4 G 3 G 2 G 1
R60 15k
R61 15k
R62 15k
R63 15k
R64 15k
R65 15k
R66 15k
R67 15k
UPLESS DOWN
info
START
AUTO MINUTE
KITCHEN TIMER
CLOCK SET
CPU UNIT CIRCUIT DIAGRAM
Page 43
R-895M - 38
Figure S-4. Printed Wiring Board of Power Unit
WH1
ZD2
1
1
CN-B
CN-A
CN-E
D12
17
(J1)
D13
CN-C
RY6
RY7
OL : TTM
CH : BH
FM
CF
91
TH
23
R6
D1 D3
MICRO
1
R4
R3
D7D6
VRS1
R5
SP1
R2
JP2
(J2)
JP3
JP4
JP1
RY2
RY1
RY3
RY4
RY5
POWER CONT
D4
D5
15
C5
C4
C3
C1
D11
D14
C2
B
BE
E
Q3
Q2
D2
PRINTED WIRING BOARD OF POWER UNIT DIAGRAM
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