Frigidaire MFM-6D, MFM-7DTP Service Manual

MICROWAVE OVEN

SERVICE MANUAL

DEFROST COOK

CLOCK

DEFROST

COOK

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2

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0

STOP/CLEAR

START

Model No.: MFM-6D

MFM-7DTP

PROPER USE AND SERVICE PRECAUTIONS...........................................................................................2

SPECIFICA TIONS...........................................................................................................................................3

FEA TURES DIAGRAM...................................................................................................................................4

INST ALLATION ...............................................................................................................................................6

OPERA TION PROCEDURE...........................................................................................................................7

CONTROLS.....................................................................................................................................................8

INTERLOCK MECHANISM FUNCTIONS AND ADJUSTMENTS..............................................................22

MEASUREMENT OF THE MICROWAVE OUTPUT POWER....................................................................24

MICROWAVE EMISSION TEST ..................................................................................................................24

WIRING DIAGRAM.......................................................................................................................................25

CIRCUIT DESCRIPTION..............................................................................................................................26

SAFETY PRECAUTIONS FOR DISASSEMBLY AND REPAIR.................................................................28

DISASSEMBL Y AND ASSEMBLY ...............................................................................................................29

TROUBLE SHOOTING GUIDE....................................................................................................................34

COMPONENT TEST PROCEDURE ...........................................................................................................41

PRINTED CIRCUIT BOARD ........................................................................................................................43

CIRCUIT CHECK PROCEDURE............................................................................................................43

P.C.B. CIRCUIT DIAGRAM......................................................................................................................48

COMPONENT INFORMA TION...............................................................................................................50

PRINTED CIRCUIT BOARD....................................................................................................................51

P.C.B. LOCA TION NO..............................................................................................................................52

EXPLODED AND P AR TS LIST....................................................................................................................53

1

PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE
ENERGY

(a) Do not operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the magnetron

or other microwave source, and make repairs as necessary: (1) Interlock operation, (2) proper
door closing, (3) seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or
loosening of hinges and latches, (5) evidence of dropping or abuse.

(c) Before turning on microwave power for any service test or inspection within the microwave

generating compartments, check the magnetron, wave guide or transmission line, and cavity
for proper alignment, integrity, and connection.

(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave

generation and transmission systems shall be repaired, replaced,or adjusted by procedures
described in this manual before the oven is released to the owner.

(e) A microwave leakage check to verify compliance with the Federal Performance Standard

should be performed on each oven prior to release to the owner.

TABLE OF CONTENTS

1. For Safe Operation
Damage that allows the microwave energy (that cooks or heats the food) to escape will result in poor
cooking and may cause serious bodily injury to the operator.
IF ANY OF THE FOLLOWING CONDITIONS EXIST. OPERATOR MUST NOT USE THE APPLIANCE.
(Only a trained service personnel should make repairs.)

1) A broken door hinge.

2) A broken door viewing screen.

3) A broken front panel, oven cavity.

4) A loosened door lock.

5) A broken door lock.
The door gasket plate and oven cavity surface should be kept clean.
No grease, soil or spatter should be allowed to build up on these surfaces or inside the oven.
DO NOT ATTEMPT TO OPERATE THIS APPLIANCE WITH THE DOOR OPEN. The microwave oven
has concealed switches to make sure the power is turned off when the door is opened. Do not attempt to
defeat them.
DO NOT ATTEMPT TO SERVICE THIS APPLIANCE UNTIL YOU HAVE READ THIS SERVICE
MANUAL.

2. For Safety Service Procedures.

1) If the oven is operative prior to servicing, a microwave emission check should be performed prior to

servicing the oven.

2) If any certified oven unit is found to have excessive emission level 5mW/cm

2

, the service person
should:
(a) inform the manufacturer, importer or assembler ,
(b) repair the unit at no cost to the owner,
(c) attempt to ascertain the cause of the excessive leakage,
(d) tell the owner of the unit not to use the unit until the oven has been brought into compliance.

3) If the oven operates with the door open, the service person should tell the user not to operate the oven
and contact the manufacturer and CDRH immediately.

2

PROPER USE AND SERVICE PRECAUTIONS

CAUTION: This Device is to be Serviced Only by Properly Qualified Service Personnel. Consult the

Service Manual for Proper Service Procedures to Assure Continued Compliance with
the Federal Performance Standard for Microwave Ovens and for Precautions to be
Taken to Avoid Possible Exposure to Excessive Microwave Energy.

* Specifications subject to change without notice.

3

SPECIFICATIONS

289

(11.4 in)

495

(19.5 in)

382

(15.0 in)

MFM-6D MFM-7DTP

POWER SUPPL Y 120V AC 60Hz SINGLE PHASE WITH GROUNDING

POWER CONSUMPTION

920W

MICROWAVE OUTPUT POWER 600W (IEC 705)

FREQUENCY 2450 MHz
OUTSIDE DIMENSIONS (WxHxD) 495x 289 x 382mm (19.5 x 1 1.4 x 15.0 in.)
CA VITY DIMENSIONS (WxHxD) 320x 225 x 330mm (12.6 x 8.9 x 13.0 in.)
NET WEIGHT APPROX. 14Kg (30.9 lbs.)
TIMER 59 min. 99 sec. 59 min. 99 sec.
POWER SELECTIONS 2 LEVELS 2 LEVELS

4

FEATURES DIAGRAM (MFM-6D)

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DEFROST COOK

CLOCK

DEFROST COOK

123
456
789

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STOP/CLEAR START

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5

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2

3

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1. Door latch–When the door is closed it will
automatically lock shut. If the door is opened
while the oven is operating, the magnetron will
automatically shut off.

2 . Door seal-The door seal maintains the

microwave within the oven cavity and prevents
microwave leakage.

3. Oven Cavity

4. Spatter shield-Protects the microwave outlet

from splashes of cooking foods.

5. Safety interlock system-Prevents the oven
from operating while the door is opened.

6. Door release button-Pushing this button
stops oven operation and opens the door.

7. Glass cooking tray-Made of special heat
resistant glass. The tray must always be in
proper position before operating.
Do not cook food directly on the tray.

8. Roller guide-Supports the glass cooking tray.

9. Door screen-Allows viewing of food.

The screen is designed so that light can pass
through, but not the microwaves.

10. Display-Cooking time & present time are
displayed.

11. Defrost-Used to defrost foods.

12. Clock-Used to set clock.

13. Cook-Used to cook.

14. Time set pad-Used to set the cooking time

and the present time.

15. Stop/Clear-Used to stop the oven operation
or to delete the cooking data.

16. Start-Used to start a selected operation.

5

FEATURES DIAGRAM (MFM-7DTP)

AM

Defrost

(Low)

PM No Or Alam On

Defront

(Low)

Cook
(Med)

Cook

(High)

Lock Time

Cook
(Med)

Cook
(High)

Porozen
Reg Lag

Beremeo

Soup

Quick On

30 Seca

Frozem

Pizea

Time 1 2 3

Alarm

Am/Pm

Start

Stop
Clear

Alarm

Stop

Baked
Potato

Dinner

Plate

To Cook:

1. Selet Power Level
or Preset from above

2. Enter cooking Time
(excopt for pecects)

3. Press Stait

To Set Time/Alam:

1. Press Time or Alarm

2. Enter desirad time

3. Select AM or PM

4. Prem Time or Alam

5. To shut off alam
Press Alarm Stop

45 6

78 9

0

AM

Defrost
(Low)

PM No Or Alam On

Defront
(Low)

Cook
(Med)

Cook
(High)

Lock Time

Cook
(Med)

Cook
(High)

Porozen
Reg Lag

Beremeo

Soup

Quick On
30 Seca

Frozem
Pizea

Time 1 2 3

Alarm

Am/Pm

Start

Stop
Clear

Alarm

Stop

Baked
Potato

Dinner

Plate

To Cook:

1. Selet Power Level
or Preset from above

2. Enter cooking Time
(excopt for pecects)

3. Press Stait

To Set Time/Alam:

1. Press Time or Alarm

2. Enter desirad time

3. Select AM or PM

4. Prem Time or Alam

5. To shut off alam
Press Alarm Stop

456

789

0

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1

5

4
7

0
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)

2
3

6

9

8

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1. Door latch–When the door is closed it will
automatically lock shut. If the door is opened
while the oven is operating the magnetron
will automatically shut off.

2. Door seal-The door seal within the oven
cavity . Prevents microwave leakage.

3. Oven Cavity

4. Spatter shield-Protects the microwave outlet

from splashes of cooking foods.

5. Safety interlock system-Prevents the oven
from operating while the door is opened.

6. Door release button-Pushing this button
stops oven operation and opens the door .

7. Glass cooking tray-Made of special heat
resistant glass. The tray must always be in
proper position before operating.
Do not cook food directly on the tray.

8. Roller guide-Supports the glass cooking
tray.

9. Door screen-Allows viewing of food.
The screen is designed so that light can pass
through, but not the microwave energy.

10. Display-Cooking time & present time are

displayed.

11. Defrost(Low)-Used to defrost foods.

12. Clock(Med)-Used to cook at medium.

13. Cook(High)-Used to cook at high.

14. Popcorn-Used to Cook Popcorn.

15. Beverage/Soup-Used to heat/re-heat

beverage/soup.

16. Quick On-Touch to set re-heat setting in 30
second increments..

17. Frozen pizza-Used to cook frozen pizza.

18. Baked Potato-Used to cook baked potato.

19. Dinner plate-Used to reheat dinner plate.

20. Time-Used to set clock.

21. Time set pad-Used to set the cooking time

and the present time.

22. Alarm-Used to set alarm.

23. Am/Pm-Used to set clock & Used to set

alarm.

24. Alarm Stop-Used to clear the alarm data.

25. Stop/Clear-Used to stop the oven operation

or to delete the cooking data.

26. Start-Used to start a selected operation.

6

1. Steady , flat location
This microwave oven should be set on a stady, flat surface.

2. Leave space behind and side
All air vents should be kept a clearance. If all vents are covered during operation, the oven may overheat
and, eventually , cause oven failure.

3. KEEP away from Radio and TV sets
Poor television reception and radio interference may result if the oven is located close to a TV, Radio, or
antenna, feeder and so on.

4. KEEP away from heating appliances and water taps
Keep the oven away from hot air, steam or splash when choosing a place to position, it, or the insulation
might be adversely affected and breakdowns occur.

5. Power supply

• Check your local power source. This microwave oven requires a current of approximately 15 amperes,

120 Volts, 60Hz grounded outlet.

• Power supply cord is about 6ft long.

1. Longer cord sets or extension cord are available and may be used if care is exercised in their use.

2. If a long cord sets or extension cords is used, (1) the marked electrical rating of the cord set or

extension cord should be at least as great as the electrical rating of the appliance, (2) the extension
cord must be a grounding-type 3-wire cord, and (3) the longer cord should be arranged so that it will
not drape over the countertop or tabletop where it can be pulled on by children or tripped over
accidentally.

6. Examine the oven when unpacking for any damage such as:
A misaligned door, Broken door, or dent in cavity.
If any of the above are visible. DO NOT INSTALL, and notify intirion corp immediately.

INSTALLATION

3-prong plug

3-prong Receptacle

Receptacle
Box cover

Grounding Lead

Receptacle Box cover

Grounding Adaptor

Receptacle

When use a grounding adaptor, make
sure the receptacle box is fully grounded

When use 3-pronged plug

7

This section includes useful information about oven operation.

OPERATION PROCEDURE

Plug power supply cord into a standard 3­pronged 15 Amp, 120V AC 60Hz power outlet
socket.

After placing the food in a suitable container,
open the oven door and put it on the glass tray.
The glass tray must always be in place during
cooking.

Shut the door. Make sure that it is firmly
closed.

When the oven door is opened, the light turn
off.

The oven door can be opened at any time
during operation by touching the door release
button on the control panel. The oven will
automatically shut off. To restart the oven,
close the door and then touch START.

Each time a pad is touched, a BEEP will
sound to acknowledge the touch.

The display will show “: 0” when the oven is
plugged in.

Time clock returns to the present time when
the cooking time ends.

When the STOP/CLEAR pad is touched
during the oven operation, the oven stops
cooking and all information retained.
To erase all information (except the present
time), touch the STOP/CLEAR pad once
more. If the oven door is opened during the
oven operation, all information is retained.

If the START pad is touched and the oven
does not operate, check the area between the
door and door seal for obstructions and make
sure the door is closed securely.
The oven will not start cooking until the door is
completely closed or the program has been
reset.

NOTE:

When the cooking time is up the time
pointer reads “0”, you can hear the beep
and the heating stops. PLEASE NOTE
THAT THE TIMER CONTINUES FOR
THREE (3) MINUTES AFTER THE
COOKING STOPS. This delays
reactivation of the refrigerator and
lengthens its useful life. Open the door
and take out the food (you need not wait
for the timer to stop to remove food). If
you wish to check the food before the end
of set time, simply open the door and the
oven will stop cooking. PLEASE NOTE
THAT THE TIMER DOES NOT STOP
when the door is open, but the oven does
stop cooking. When the door is closed,
the oven will resume cooking
automatically. Cooking time can be reset
at any time during the cooking operation
by turning the timer knob. PLEASE NOTE
THAT THE REFRIGERATOR IS OFF
DURING THE MICROWAVE OVEN USE.

NOTE: Make sure the oven is properly installed and plugged into the electrical outlet.

1

2

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5

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7
8
9

10

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When the oven is first plugged in, the display will flash ":0" and a tone will sound. If the AC power ever goes
off, the display shows ":0" when the power comes back on.

DO THIS...

1. Touch CLOCK pad.

THIS HAPPENS...

This is a 12 hour clock system.

CONTROLS (MFM-6D)

SETTING THE CLOCK

NOTE: If you attempt to enter an incorrect time, the time will not be set and a error signal tone will

sound. Touch the CLOCK pad and re-enter the time.

CLOCK

2. Touch CLOCK pad once
more.

This is a 24 hour clock system.

CLOCK

4. Touch CLOCK pad.

The display will stop blinking, and the colon starts blinking.
If you selected 12 hour clock system, this digital clock allows you to set from 1:00
to 12:59.
If you selected 24 hour clock system, this digital clock allows you to set from 0:00
to 23:59.

CLOCK

DEFROST COOK

DEFROST COOK

3. Enter the correct time of day

by touching the numbers in
sequence.

The display will then begin
blinking.

1 2 3 0

DEFROST COOK

NOTE:

This oven has multiple
clock systems. If you want
12 hour clock system, omit
this step.

9

When DEFROST is selected, the automatic cycle divides the defrosting time into periods of alternating
defrost and stand times by cycling on and off.

DEFROSTING

DO THIS...

1. Touch DEFROST pad.

THIS HAPPENS...

The DEFROST indicator lights
and “ :0” is displayed.

DEFROST

DEFROST COOK

3. Touch START pad.

When you touch START pad, the DEFROST indicator starts blinking to show the
oven is in the DEFROST mode. The display counts down the time to show you
how much defrosting time is left in the DEFROST mode. The oven beeps during
the defrosting cycle to signal that the food needs to be turned or rearranged.
When the defrosting time ends, you will hear 3 beeps.

ST ART

2. Touch number pads for the
defrosting time you want.

The display will show the
numbers you pressed in the
order you touched.

2 7 1 0

DEFROST COOK

NOTE: Your oven can be

programmed for 59
minutes 99
seconds. (59:99)

10

COOKING

DO THIS...

1. Touch COOK pad.

THIS HAPPENS...

The COOK indicator lights and “
:0” is displayed.

COOK

DEFROST COOK

3. Touch START pad.

When you touch ST ART pad, the COOK indicator starts blinking to show the oven
is cooking. The display counts down the time to show how much cooking time is
left. When the cooking time ends, you will hear 3 beeps.

ST ART

2. Touch nunber pads for the
cooking time.

The display will show the
numbers you pressed in the
order you touched.

5 3 0

DEFROST COOK

NOTE: Your oven can be

programmed for
59 minutes 99
seconds. (59:99)

11

Some recipes require frozen foods to be thawed before cooking.
This oven can be programmed to automatically defrost foods before cooking

DEFROSTING AND COOKING

DO THIS...

1. Touch DEFROST pad.

THIS HAPPENS...

The DEFROST indicator lights
and “ :0” is displayed.

DEFROST

DEFROST COOK

2. Touch number pads for the

defrosting time you want.

The display will show the
numbers you pressed in the
order you touched.

2 7 1 0

DEFROST COOK

NOTE: Your oven can be

programmed for 59
minutes 99
seconds. (59:99)

3. Touch COOK pad.

The COOK indicator lights and "
:0" is displayed.

DEFROST COOK

4. Touch number pads for the

cooking time.

The display will show the
numbers you pressed in the
order you touched.

5 3 0

DEFROST COOK

NOTE: Your oven can be

programmed for 59
minutes 99
seconds. (59:99)

COOK

12

DO THIS...

5. Touch START pad.

THIS HAPPENS...

When you touch ST AR T pad, the DEFROST and COOK indicator lights come on.
The DEFROST indicator light starts blinking to show you that the oven is in
DEFROST mode. The display counts down the time remaining in DEFROST
mode.
Turn over, break and redistribute food when it beeps. At the end of DEFROST
mode, the oven will beep and start COOK mode.
The DEFROST indicator goes off and the COOK indicator starts blinking. The
display counts down the time remaining in the COOK mode. When the cooking
time ends, you will hear 3 beeps.

ST ART

1. Press STOP/CLEAR pad.

• Y ou can restart the oven by touching START pad.

• Touch STOP/CLEAR once more to erase all instructions.

• Y ou must enter in new instructions.

2. Open the door.

• Y ou can restart the oven by closing the door and touching START.

TO STOP THE OVEN WHILE THE OVEN IS OPERATIN

NOTE: Oven stops operating when door is opened.

13

When the oven is first plugged in, the display will flash “:0” and a tone will sound. If the AC power ever goes
off, the display will flash “:0” when the power comes back on.

DO THIS...

1. Touch TIME pad.

THIS HAPPENS...

This is a 12 hour clock system.
If you touch TIME pad once
more, the display will show 24H.

CONTROLS (MFM-7DTP)

SETTING THE CLOCK

NOTE: If you attempt to enter an incorrect time, the time will not be set and a error signal tone will

sound. Touch the TIME pad and re-enter the time.

TIME

2. Enter the correct time of day
by touching the numbers in
sequence.

4. Touch TIME pad.

The colon starts blinking.
If you selected 12 hour clock system, this digital clock allows you to set from 1:00
to 12:59.
If you selected 24 hour clock system, this digital clock allows you to set from 0:00
to 23:59.
If the clock (or display) shows any abnormality, unplug the oven from the AC
outlet. Plug it in again and then reset the clock.

TIME

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

3. Touch AM/PM pad.

Touch AM/PM to change desired
indicator.

1 2 3 0

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

NOTE:

If you select 24H system,
AM/PM bar segment will
be off.

TIME

14

Y our oven has an alarm clock feature.
When the display shows the present time “:0”, set the alarm.

DO THIS...

1. Touch ALARM pad.

THIS HAPPENS...

The AM indicator lights and “ :0”
is displayed. And the ALARM
ON indicator starts blinking.

SETTING THE ALARM

ALARM: When the alarm is activated, the alarm buzzer will sound intermittently until ALARM STOP

is touched. If the ALARM STOP button has not been touched within a 10 minute period,
the ALARM buzzer will be shut off automatically .

REMEMBER:

•

To change setting time, touch ALARM and set the desired time according to instructions above.

•

To stop the alarm, just touch ALARM STOP. Buzzer stops and clock display reappears.

•

To check the preprogram alarm time, touch ALARM. The preprogram time appears in the display window .

NOTE: If clock is changed from a 12 hour to a 24 hour system or from a 24 hour to a 12 hour system, you

MUST reset the ALARM in the appropriate 12 or 24 hour system. To reset alarm, follow
instructions listed above (Steps 1-4). Otherwise, the alarm will not sound at the selected time due
to the difference between the two clock systems.

NOTE: If you attempt to enter an incorrect time, the time will

not be set and a error signal tone will sound.

ALARM

2. Enter the desired alarm
setting by touching the
numbers in sequence.

4. Touch ALARM pad.

The alarm is set.

ALARM

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

3. Touch AM/PM pad.

The display shows am or pm
and touch AM/PM to change
desired indicator.

Follow step 3 for 12 hour clock system only. For 24 hour clock system, skip to step 4

5 3 0

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

AM/PM

15

This basic microwave cooking method allows you to cook food for a desired time.
Foods with high moisture content such as fish should be cooked on maximum power, as this is the fastest

cooking method and best maintains the natural flavor and texture of the foods.

DO THIS...

1. Touch COOK(HIGH) pad.

THIS HAPPENS...

The COOK(HIGH) indicator
lights and “:0” is display.
And the TIME indicator starts
blinking.

THE COOKING (COOK HIGH)

NOTE: If you attempt to enter an incorrect time, the time will not be set and an error signal will sound.

COOK (HIGH)

2. Touch number pads for the
cooking time.

The Time indicator stops
blinking. The display will show
the numbers you pressed in the
order you touched.

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

3. Touch STAR T pad.

When you touch START pad, the TIME indicator goes off to show the
oven is cooking. The display counts down the time to show how much
cooking time is left.
When the cooking time ends, you will hear 3 beeps.

2 3 0

NOTE:

Your oven can be

programmed for 59 min99sec

ST ART

16

This basic microwave cooking method allows you to cook food for a desired time.
Foods with medium moisture content such as beef should be cooked on medium power, as this is the

fastest cooking method and best maintains the natural flavor and texture of the foods.

TIME COOKING (COOK MEDIUM)

DO THIS...

1. Touch COOK(MED) pad.

THIS HAPPENS...

The COOK(MED) indicator lights
and “:0” is display .
And the TIME indicator starts
blinking.

COOK(MED)

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

2. Touch number pads for the
cooking time.

The Time indicator stops
blinking. The display will show
the numbers you pressed in the
order you touched.

1 0 0 0

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

NOTE:

Your oven can be
programmed for 59
min99sec

NOTE: If you attempt to enter an incorrect time, the time will not be set and an error signal will sound.

3. Touch STAR T pad.

When you touch START pad, the TIME indicator goes off to show the
oven is cooking. The display counts down the time to show how much
cooking time is left.
When the cooking time ends, you will hear 3 beeps.

ST ART

17

AUTO DEFROSTING (DEFROST LOW)

DO THIS...

1. Touch DEFROST (LOW) pad.

THIS HAPPENS...

The DEFROST (LOW) indicator
lights and “:0” is display. And the
TIME indicator starts blinking.

DEFROST(LOW)

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

3. Touch START pad.

When you touch START pad, the Time indicator goes off to show the oven is in
the DEFROST mode. The display counts down the time to show you how much
defrosting time is left in the DEFROST mode.
The oven beeps during the defrosting cycle to signal that the food needs to be
turned or rearranged.
When the defrosting time ends, you will hear 3 beeps.

ST ART

2. Touch number pads for the
defrosting time you want.

The Time indicator stops
blinking. The display will show
the numbers you pressed in the
order you touched.

2 6 8 0

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

NOTE: Your oven can be

programmed for
59 min99sec

NOTE: If you attempt to enter an incorrect time, the time will not be set and an error signal will sound.

When DEFROST is selected, the automatic cycle divides the defrosting time into periods of alternating
defrost and stand times by cycling on and off.

18

This simplified control lets you set and start micrwave cooking up to 5 minutes by just pressing 2 key pads.
The power level is always set to HI (maximum power) for Quick-on cooking.

Press the QUICK ON keypad until desired cooking time appears in the display.
The QUICK ON key pad increases the cooking time by 30 second increments each time it is touched.

QUICK-ON COOKING (HI-POWER)

DO THIS...

1. Touch QUICK ON pad.

THIS HAPPENS...

When you touch QUICK ON
pad, “:30” is displayed. The
cooking time appears in the
display.

QUICK ON

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

NOTE: You may open the door to stop cooking before the selected time is over.

To start again, close the door and touch START.

2. Touch STAR T pad.

The oven begins cooking and display shows time counting down.
When the cooking time ends, you hear 3 beeps.

ST ART

Cooking Time

30 seconds

1 minutes

1 min 30 sec.

2 minutes

2 min 30 sec.

3 minutes

3 min 30 sec.

4 minutes

4 min 30 sec.

5 minutes

Touch QUICK ON

once

twice
3 times
4 times
5 times
6 times

7 timies

8 times
9 times

10 times

19

NOTE: 1. Use pre-packaged room-temperature microwave popcorn.

2. Place bag in oven according to manufacturer’s directions.

3. Pop only one bag at a time.

4. After popping, open bag carefully, popcorn and steam are extremely hot.

5. Do not reheat unpopped kernels or reuse bag.

6. Do not leave oven unattended while popping popcorn.

CAUTION: 1. If pre- packaged popcorn is of a different weight than the recommended weight, do not

use the popcorn setting, or inadequate popping or a fire may occur. Follow the
manufacturer’s instructions.

PRESETS

DO THIS...

1. Touch POPCORN pad.

THIS HAPPENS...

When you touch POPCORN
pad, “3.5” is displayed.
Select bag size as follows.

POPCORN

The display changes to cooking time counting down.
When the cooking time ends, you will hear 3 beeps.

2. Touch STAR T pad.

ST ART

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

Cooking with Preset allows you to cook or reheat many of your favorite foods by touching the appropriate
Preset button. To increase cooking time touch preset button repeatedly until the correci cooking time
appears on the display .

DO THIS...

1. Touch BEVERAGE/SOUP
pad.

THIS HAPPENS...

When you touch
BEVERAGE/SOUP pad, “3:50”
is displayed.
Select cook time as follows.

BEVERAGE/SOUP

The display changes to cooking time counting down.
When the cooking time ends, you will hear 3 beeps.

2. Touch STAR T pad.

ST ART

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

ƒR BEVERAGE(2:50)/SOUP(3:50) ƒR

•

Beverage: Touch BEVEAGE/SOUP once.

• Soup: T ouch BEVERAGE/SOUP twice.

ƒR POPCORN ƒR

• 3.5oz: T ouch POPCORN once.

• 1.75oz: T ouch POPCORN twice.

20

NOTE: 1. Use only one frozen pizza at a time.

2. Use only frozen pizza recommended for microwave oven.

3. If the cheesce of frozen pizza does not melt sufficiently , cook a few seconds longer .

DO THIS...

1. Touch FROZEN PIZZA pad.

THIS HAPPENS...

When you touch FROZEN
PIZZA pad, “7” is displayed.
Select pizza size as follows.

FROZEN PIZZA

The display changes to cooking time counting down.
When the cooking time ends, you will hear 3 beeps.

2. Touch START pad.

ST ART

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

ƒR FROZEN PIZZA ƒR

•

7oz: Touch FROZEN PIZZA once.

• 10oz: T ouch FROZEN PIZZA twice.

DO THIS...

1. Touch BAKED POTATO pad.

THIS HAPPENS...

When you touch BAKED
POT ATO pad, “1” is displayed.
Select number of potatoes as
follows.

BAKED POT ATO

The display changes to cooking time counting down.
When the cooking time ends, you will hear 3 beeps.

2. Touch START pad.

ST ART

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

ƒR BAKED POT ATO ƒR

•

1 for 1 Potato: Touch BAKED POTATO once.

• 2 for 2 Potatoes: T ouch BAKED POTAT O twice.

• 3 for 3 Potatoes: T ouch BAKED POTAT O three times.

21

DO THIS...

1. Touch DINNER PLATE pad.

THIS HAPPENS...

When you touch DINNER
PLA TE pad, “11” is displayed.

DINNER PLA TE

The display changes to cooking time counting down.
When the cooking time ends, you will hear 3 beeps.

2. Touch START pad.

ST ART

AM PM No Oz Alarm On

Defrost Cook Cook
(Low) (Med) (High) Lock Time

ƒR DINNER PLA TE ƒR

•

1 1oz: Touch DINNER PLA TE once only.

CHILD SAFETY LOCK

TO STOP THE OVEN WHILE THE OVEN IS OPERATING

The safety lock prevents unwanted oven operation such as by small children.
To set, press and hold STOP/CLEAR for 3 seconds, LOCK indicator lights.
To cancel, press and hold STOP/CLEAR for 3 seclnds, LOCK indicator goes off.

1. Press STOP/CLEAR pad.

• You can restart the oven by touching START pad.

• T ouch ST OP/CLEAR once more to erase all instructions.

• You must enter in new instructions.

2. Open the door.

• You can restart the oven by closing the door and touching START.

NOTE: Oven stops operating when door is opened.

22

The door lock mechanism is a device has been specially designed to completely eliminate microwave
radiation when the door is opened during operation, and thus to perfectly prevent the danger resulting from
the leakage of microwave.

(1) Primary interlock switch

When the door is closed, the hook locks the oven door. If the door is not closed properly, the oven will not
operate. When the door is closed, the hook pushes the button of the micro switch. Then the button of the
primary interlock switch bring it under on condition.

Adjustment 1.
When the door is closed, the switch button is
pushed by the hook.
The movement of the switch button should exceed

1.2mm measured at the top of the button.

INTERLOCK MECHANISM FUNCTIONS AND ADJUSTMENTS

Latch

Mounting screw

Button

Primary interlock switch

Hook

1.2mm

Latch Mounting screw Hook Button Primary interlock switch 1.2mm

23

(2) Secondary interlock switch and interlock monitor switch

When the door is closed, the hook pushes the push lever down ward, and push lever presses the button
of the interlock monitor switch to bring it under "off", condition and presses the button of the secondary
interlock switch to bring it under "on", condition.

Adjustment 2.

Interlock monitor switch
When the door is closed, the interlock monitor switch should be opened before other switches close.
When the door is opened, the interlock monitor switch should be closed after other switches open.

Secondary interlock switch
The movement of the switch button should exceed 1.2mm measured at the top of the button.

(3) Adjustment steps

a) Loosen the two mounting screws.
b) Adjust interlock switch assembly position.
c) Confirm the gap (1.2mm) described above.
d) Make sure that push lever moves smoothly after adjustments is completed.
e) Completely tighten the two mounting screws.

(4) Interlock switch resplacement

Whenever safety interlock switches are replaced:

1) Refer to the following diagram.

2) Check the connection of monitor switch after replacement.

3) Perform the electrical continuity check of interlock switches and microwave emission test mentioned in
this manual.

Interlock
monitor
switch

Hook

Push lever

Secondary
interlock
switch

NOTE: Microwave emission test should be performed after adjusting interlock mechanism. If the

microwave emission exceed 4mW/cm

2

, readjust interlock mechanism.

GN BL

Secondary
Interlock
Switch

BK

RD

Interlck
Monitor
Switch

BL

BK

RD

WH BK

Primary
Interlock
Switch

SYMBOL COLOR

RD RED

BL BLUE

BK BLACK
GN GREEN
WH WHITE

24

Microwave output power can be checked by indirectly measuring the temperature rise of a certain amount of
water exposed to the microwave as directed below.

1) Microwave power output measurement is made with the microwave oven supplied at rated voltage and
operated at its maximum microwave power setting with a load of 1,000±5cc of potable water.

2) The water is contained in a cylindrical borosilicate glass vessel having a maximum material thickness of 3
mm and an outside diameter of approximately 190mm.

3) The oven and the empty vessel are at ambient temperature prior to the start of the test.
The initial temperature of the water is 10±2°C (50±3.6°F).
It is measured immediately before the water is added to the vessel. After addition of the water to the
vessel, the load is immediately placed on the center of the shelf which is in the lowest normal position

4) Microwave power is switched on.

5) Heating time should be exactly 69 seconds.
Heating time is measured while the microwave generator is operating at full power.
The filament heat-up time for magnetrons is not included.

6) The initial and final water temperatures are selected so that the maximum difference between the
ambient and final water temperatures is 5K.

7) The microwave power output P in watts is calculated from the following formula:

• ¡ T is actual temperature rise.

• t is the heating time.

The power measured should be 600W±10%.

WARNING
Make sure to check the microwave leakage before and after or adjustment.

• Always, start measuring of an unknow field to assure. Safety for operating personnel from microwave
energy.

• Do not place your hands into any suspected microwave radiation field unless the safe density level is
known.

• Care should be taken not to place the eyes in direct line with the source of microwave energy.

Procedure
A) Prepare Microwave Energy Survey Meter, 600cc glass breaker , glass thermometer 100°C or 212°F.
B) Pour 275cc±15cc of tap water initially at 20±5°C (68±9°F) in the 600cc beaker with an inside diameter of

approx. 8.5 cm (3.5 in).

C) Place it at the center of the tray and set it in a cavity.
D) Close the door and operate the oven.

MEASUREMENT OF THE MICROW AVE OUTPUT POWER

MICROW AVE EMISSION TEST

P = 4187 X ¡ T/t

Water Load

Tray

CAUTION:

1. Water load should be measured exactly to 1 liters.

2. Input power voltage should be exactly 120 volts as specified.

3. Ambient temperature should be 20±2°C (68±3.6°F)

25

E) Measure the leakage by using microwave energy survery meter with dual ranges, set to 2,450 MHz.

– Measured radiation leakage must not exceed the values prescribed below.

• Leakage for a fully assembled oven with door normally closed must be less than 4mW/cm

2

.

– When measuring the leakage, always use the

5cm space cone with probe. Hold the probe
perpendicular to the cabinet, door. Place the
space cone of the probe on the door, cabinet,
door seam, along the seam, the door viewing
window, the exhaust air vents, the suction air
vents.

– Measuring should be in a counter-clockwise

direction at a rate of 1 inch/sec. If the leakage
of the cabinet door seam is unknow, move the
probe more slowly .

– When measuring near a corner of the door,

keep the probe perpendicular to the areas
making sure the probe end at the base of the
cone does not get closer than 2 inches from
any metal. If it does, erroneous reading may
result.

WIRING DIAGRAM

FM

POWER SUPPLY:
SINGLE PHASE~ONLY

LIVE

RD

FUSE

THERMOSTAT

RD

RD

BK

PRIMARY
INTERLOCK
SWITCH(UPPER)

WH

LR

RD

HIGH VOLTAGE
TRANSFORMER

OR OR

H.V.
CAPACITOR

MAGNETRON

H.V. DIODE

GY

GY

SECONDARY
INTERLOCK SWITCH

BL

GN

BL

GY GY

RELAY-1

RELAY-2

CONTROL P.W.B. ASS'Y

NEUTRAL

GY

3

2

1

INTERLOCK
MONITOR
SWITCH

GN

NOTE : RD : RED
WH : WHITE
BK : BLACK
GN : GREEN
BR : BROWN

OR : ORANGE
BL : BLUE
GY : GRAY
GE : GREEN/YELLOW

CL : CAVITY LAMP
FM : FAN(BLOWER) MOTOR
GM : GEARED MOTOR

[CONDITION]
DOOR : CLOSED
COOK : OFF

!

W

@

G

#

RELAY-3

GY

WH
GN

RD

BK

WH

CL GM

BL

WH

S/N : 3513505900

POWER OUTPUT
SOCKET

(Fig. 1)

26

Refer to the "WIRING DIAGRAM" Fig. 1 on page 25.

MICROWAVE COOKING
TIME COOKING

1. When the food is placed inside the oven and door is closed.

1) The low voltage transformer supplies the necessary voltage to the touch control circuit when the power

cord is plugged in.

2) The contacts of the interlock monitor switch open.

This switch creates short circuit to blow 15A fuse and stop magnetron oscillation when door is opened
during operation under abnormal condition (i.e. the contacts of primary interlock switch do not open the
circuit).

3) The contacts of primary interlock switch close the primary circuit.

2. When cooking cycle, power and time are set by touching the function pads and the desired

numerical pads.

1) The function indicating bars are located on the digitron light to indicate that function have been set.

2) The time you set appears in the display window.

3) The touch control circuit memorizes the cooking program you set.

3. When the start pad is touched.

* The RELA Y "1" and "2" are controlled by the touch control circuit.

1) 120V AC is applied to the high voltage transformer through the contacts of RELA Y "1" (See Fig. 1)

2) Fan motor starts rotating and cools the magnetron by blowing the air coming from the intake on the

rear plate hole.

3) The oven lamp light the inside of the oven.

4) Indicator light turns on to indicate function operation. Cooking time starts count down.

5) 3.3 Volts AC is generated from the filament winding of the high voltage transformer. This filament

voltage is applied to the magnetron to heat the magnetron filament through two noise prventing choke
coils.

6) A high voltage of 2000 Volts ACis generated in the secondary of high voltage transformer and this

secondary voltage is increased by the action of the diode and the charging of the high voltage
capacitor. This resultant DC voltage is then applied to the anode of the magnetron. As shown in Fig. 3
the first half cycle of the high voltage produced in the high voltage transformer secondary charges the
high voltage capacitor. Current flow is in the direction of the dotted-line during the second half cycle, the
voltage produced by the transformer secondary, and the charge of the high voltage capacitor are
combined and applied to the magnetron as shown by the solid line so that oscillations begin. The
disturbance wave generated by the magnetron is prevented by the choke coils of 3.2µH, filter
capacitors of 16pF and the magnetron's shielded case so that TV and radio programs are not impaired
by noise.

CIRCUIT DESCRIPTION

27

4. When the door is opened during cooking.

1) The primary interlock switch is opened to cut off primary voltage to the high voltage transformer to stop

microwave oscillation.

2) The secondar interlock switch is opened to give the door open information to touch control circuit. The

contacts of the RELA Y "1" and "2" open, the display stops counting down.

3) Fan motor and turn table stop rotating.

4) The oven lamp turns off.

5) As soon as the door is opened, the interlock monitor switch contacts close and creats the short circuit.

6) If the contacts of primary interlock switch malfunction the 15A fuse blows open due to the large current

surge caused by the short circuit activiation, and this in turn stops magnetorn oscillation (Fig.1).

5. When the STOP/CLEAR pad is touched during cooking.

1) The touch control circuit cuts the voltage supplied to the RELAY "1" coil and causes the magnetron to

stop oscillating.

2) RELA Y "2" turns off.

3) The display will show the time of day. If you don't set the clock, the display will show a colon.

4) The ovne lamp turns off.

5) Fan motor and turn table motor stop rotating.

OR FA

F

OR

H.V. CAPACITOR

H.V. DIODE

MAGNETRON

WIRING COLOR
OR: ORANGE

H.V. TRANSFORMER

Fig. 2

28

– Cautions to be observed when trouble shooting.
Unlike many other appliances, the microwave oven is a high-voltage, high-current equipment. It is

completely safety during normal operation. However, carelessness in servicing the oven can result in an
electric shock or possible danger from a short circuit.

(1) Always remove the power plug from the outlet before servicing.
(2) Use an insulated screwdriver which is attached to iron plate, and wear rubber gloves when servicing the

high voltage side.

(3) Warning about the electric charge in the high voltage capacitor. When inspecting and repairing the high

voltage side, always short the capacitor terminals and make sure of discharge.

1. Check the grounding.

Do not operate on a 2-wire extension cord.
The microwave oven is designed to be used
when grounded.
It is imperative, therefore, to makes sure it is
grounded properly before begining repaire work.

2. Warning about the electric charge in the high

voltage capacitor.

For about 30 seconds after the operation stops,
electric charge remains in the high voltage
capacitor. When replacing or checking parts,
short between oven chassis and the negative
high terminal of the high voltage capacitor, by
using a properly insulated screw driver to
discharge.

(4) When the 15 Amp. fuse is blown out due to

operation of the monitor switch, replace primary,
secondary , and monitor switch.
Refer to 22~23page for the necessary
adjustment.

(5) After repair or replacement of parts, make sure that the screws are properly tightened, and all electrical

connections are tightened.

(6) Do not operate without cabinet.

SAFETY PRECAUTIONS FOR DISASSEMBLY AND REP AIR

Short

CAUTION: Service personnel should remove their watches whenever working close to or repairing

the magnetron.

WARNING: When servicing the appliance, need a care of touching or replacing high potential parts

because of electrical shock or exposing microwave. These parts are as follows – H.V.
Transformer , Magnetron, H.V. Capacitor , H.V. Diode.

29

1. T o remove cabinet.

Remove three screws (F02).

2. T o remove door assembly.

1) Remove two screws (F41) which secure the

top hinge stopper (A03).

2) Remove the door assembly (A00) from top

plate.

3) Reverse the above for reassembly.

3. T o remove door parts.

DISASSEMBLY AND ASSEMBL Y

F02

F41

A00

A03

A01

A02

A04

A03

A06

A05

A07

A08

30

(1) Remove the gasket door (A06) from door plate.
(2) Remove the barrier screen inner (A05) from door plate.
(3) Remove the door frame (A02) from door plate.
(4) Remove the top hinge stopper (A03) from door plate.
(5) Remove the spring (A08) and the hook (A07).
(6) Remove the barrier screen outer (A01) from door frame (A02).
(7) Reverse the above steps for reassembly.

4. Method to reduce the gap between the door
seal and the oven front surface.

(1) To reduce gap located on part 'A'.

1) Remove the cabinet.

2) Loosen two screws on the top hinge
stopper, then push the door to contact the
door seal to oven front surface.

3) Tighten two screws.

(2) To reduce gap located on part 'B'.

1) Loosen three screws on under hinge stopper, then push the door to contact the door seal to
oven front surface.

2) Tighten three screws.

(3) To reduce gap located on part 'C'. (See Fig. 5)

1) Remove the cabinet.

2) Loosen a screw on interlock switch assembly located top of oven body.

3) Draw the interlock switch assembly inward as possible to engage with hook on the door
bottom.

4) Tighten a screw .

(4) To reduce gap located on part 'D' (See Fig. 6)

1) Remove the cabinet.

2) Loosen a screw on interlock switch assembly located bottom of oven body.

3) and (4) are same as step (3).

AC

BD

Hook

Mounting screw

Secondary
interlock
switch

Hook

Mounting screw

Primary
interlock
switch

NOTE: A small gap may be acceptable if the microwave leakage does not exceed 4mW/cm

2

Fig. 5 Fig. 6

31

5. T o remove control panel assembly.

(1) Disconnect all the lead wires connected to

control panel assembly .

(2) Remove the screw holding the control panel

assembly.

(1) Remove the three screws (B04) from the P.C.B. ass'y (B03).
(2) Pull out the P.C.B. ass'y (B03) from the control panel (B02).
(3) Remove the door open lever (B05).
(4) Pull out the door open button (B07) and button spring (B06) from the control panel (B02).
(5) Reverse the above steps for reassembly.

NOTE: Do not attempt to remove switch membrane except for replacement.

B01

B02

B03

B04

B05

B06

B07

32

6. T o remove high voltage capacitor .

(1) Remove the screw (F17) which secure the

grounding ring terminal of H.V diode (F20)
and the capacitor holder (F18).

(2) Remove the H.V diode (F20) from the

capacitor holder (F18).

(3) Reverse the above steps for reassembly.

High voltage circuit wiring

7. T o remove magnetron.

(1) Remove three screws (F11) holding the

magnetron (F10).

(2) Pull out the magnetron (F10) from the wave

guide.

(3) Reverse the above steps for reassembly.

F20

F18

F17

F19

MAGNETRON

H.V. CAPACITOR

H.V. DIODE

H.V. TRANS

F10

F11

33

8. To remove fan motor assembly.

(1) Remove two screws (F12) which secure the back cover (F14) from the cavity outer.
(2) Remove two screws (F13) which secure the fan motor (F15) from the back cover (F14).
(3) Pull out the fan (F16) from the fan motor (F15)
(4) Reverse the above for reassembly .

9. To remove transformer .

(1) Remove the four screws (F22) holding the

H.V. transformer (F21).
(2) Remove the H.V. transformer (F21).
(3) Reverse the above steps for reassembly .

Metallic
gasket
plate

Magnetron
antenna

Filament
terminal

Magnetron

Cooling fin

F16

F15

F14

F12

F13

F12

F22

F21

Wave guide Magnetron antenna

Metallic gasket plate

CAUTION: Never install the magnetron without the metallic gasket plate which is packed with each

magnetron to prevent microwave leakage. Whenever repair work is carried out on
magnetron, check the microwave leakage. It shall not exceed 4mW/cm

2

for a fully

assembled oven with door normally closed.

34

Following the procedures below to check if the oven is defective or not.

1. Check grounding before checking trouble.

2. Be careful of the high voltage circuit.

3. Discharge the high voltage capacitor. (see page 28)

4. When checking the continuity of switches or of the high voltage transformer, disconnect one lead wire
from these parts and then check continuity with the AC plug removed. To do otherwise may result in
false reading or damage to your meter.

5. Do not touch any part of the circuity on the touch control circuit since static electric discharge may
damage this control panel.
Always touch yourself to ground while working on this panel to discharge any static charge built up in
your body .

First of all operate the microwave oven following the correct operation described on pages 7~21 by time
cooking, in order to find the exact cause of any trouble.

(TROUBLE 1) The following visual conditions indicate a probable defective touch control circuit or

membrane switch assembly.

TROUBLE SHOOTING GUIDE

1. Incomplete segments.
(A) Segments missing.
(B) Partical segments missing.
(C) Digit flickering other than normal fluorescent

slight flickering.

(D) ":0" does not display when power is on.

2. A distinct change in the brightness of one or
more numbers in the display .

3. One or more digits in the display are not on
when they should be.

4. Display indicates a number different from one
touched.

5. For example, touch 5 and 3 appears in the
display.

6. Specific numbers (for example 5 and 3) will not
display when the panel is touched.

7. Display does not count down or up with time
cooking or clock operation.

8. Oven is programmable and cooks normally but
no display shows.

9. Display obviously jumps in time while counting
down.

10. Display counts down noticeably too fast while
cooking.

11.Display does not show the time of day when
dear pad is touched (in clock mode).

12. Oven lamp and fan motor and turn table motor
do not stop although cooking is finished.
Check if the RELAY "2" contacts close if they
are close, replace touch control circuit.

DEFROST COOK

35

(TROUBLE 2) Digital readout display does not show programming, even if the membrane keyboard

is programmed by touching proper pads.

MEMBRANE KEYBOARD CHECK PROCEDURE

1. Check the pad

Condition

Check

CauseResult Remedy

Display does not
show programming
at all,even if
keyboard is
touched

Check each pad for
continuity of the
membrane keyboard
for the following
keyboard check
procedure

Normal

Abnormal

Malfunction
of touch
control
circuity of
control box
sub-assembly

Replace
control
box sub­assembly

Malfunction
of the memb­rane keyboard

Replace the
membrane
keyboard

NOTE: Before following the particular steps listed above in the trouble shooting guide for the

membrane keyboard, failure, please check for the continuity of each wire-harness between
the membrane keyboard and control box assembly .

A

B

C

D

E

F

G

H

I

J

K

1

2

3

4

5

6

7

8

9

10

11

PCB Termination PCB Connector

DEFROST COOK

CLOCK

DEFROST COOK

123
456
789

0

STOP/CLEAR START

AM

Defrost
(Low)

PM No Or Alam On

Defront

(Low)

Cook
(Med)

Cook
(High)

Lock Time

Cook
(Med)

Cook

(High)

Porozen
Reg Lag

Beremeo

Soup

Quick On

30 Seca

Frozem

Pizea

Time 1 2 3

Alarm

Am/Pm

Alarm

Stop

Start

Stop
Clear

Baked
Potato

Dinner

Plate

To Cook:

1. Selet Power Level
or Preset from above

2. Enter cooking Time
(excopt for pecects)

3. Press Stait

To Set Time/Alam:

1. Press Time or Alarm

2. Enter desirad time

3. Select AM or PM

4. Prem Time or Alam

5. To shut off alam
Press Alarm Stop

45 6

78 9

0

JI-811 F3A

Fig. 7

MFM-6D MFM-7DTP

36

2. T ype of encoding and pad names.

The membrane keyboard consists of 15 keys (MFM-6D), 25 keys (MFM-7DTP) whose configurations are
described in Fig. 8 and provide 11 pad terminations to be connected to the touch control circuit as Fig. 7

3. Key check procedure.

To determine if the membrane keyboard is defective or not, check the continuity of each pad (KEY)
contacts with a multimeter .

F

G

H

I

J

K

E D C B A

98765

43210

STOP/
CLEAR

CLOCK DEFROST COOK START

F

G

H

I

J

K

E D C B A

98765

43210

STOP/
CLEAR

START AM/PM ALARM

POPCORN

FROZEN
PIZZA

DINNER
PLATE

BEVERAGE
SOUP

ALARM
STOP

QUICK
ON

BAKED
POTATO

TIME DEFROST

(LOW)

COOK
(MED)

START
(HIGH)

Fig. 8 Key Matrix (MFM-6D) Fig. 8 Key Matrix (MFM-7DTP)

1) 9 pad : Between F and E

2) 8 pad : Between F and D

3) 7 pad : Between F and C

4) 6 pad : Between F and B

5) 5 pad : Between F and A

6) 4 pad : Between G and E

7) 3 pad : Between G and D

8) 2 pad : Between G and C

9) 1 pad : Between G and B

10) 0 pad : Between G and A

11) STOP/CLEAR pad : Between K and E

12) CLOCK pad : Between K and D

13) DEFROST pad : Between K and C

14) COOK pad : Between K and B

15) ST AR T pad : Between K and A

1) 9 pad : Between F and E

2) 8 pad : Between F and D

3) 7 pad : Between F and C

4) 6 pad : Between F and B

5) 5 pad : Between F and A

6) 4 pad : Between G and E

7) 3 pad : Between G and D

8) 2 pad : Between G and C

9) 1 pad : Between G and B

10) 0 pad : Between G and A

11) STOP/CLEAR pad : Between K and E

12) TIME pad : Between K and D

13) DEFROST (LOW) pad : Between K and C

14) COOK (MED) pad : Between K and B

15) ST AR T pad : Between J and E

16) COOK (HIGH) Pad : Between K and A

17) AM/PM Pad : Between J and D

18) ALARM Pad : Between J and C

19) ALARM STOP Pad : Between J and A

20) POPCORN Pad : Between I and E

21) FROEN PIZZA Pad : Between I and D

22) BEVERAGE Pad : Between I and C

23) QUICK ON Pad : Between I and A

24) DINNER PLA TE Pad : Between I and D

25) BAKED POT ATO Pad : Between I and A

1. MFM-6D

1. MFM-7DTP

37

(TROUBLE 3) The oven does not operate at all; Display window does not display any figures and any

inputs can not be accepted.

Condition

Check

CauseResult Remedy

Check continuity
Interlock Monitor
switch with door
closed.

Continuity

Malfunction of
Interlock monitor
switch

Replace Primary
Interlock Switch
and Secondary
Interlock Switch
and monitor
Interlock Switch

15A fuse
blows

No
continuity

Check continuity
of both Primary
Interlock Switch
contact with door
partially open until
interlock monitor
switch contact
close.

Continuity

Shorted contacts
of primary inter­lock switch.

Check continuity
of primary
winding of low
voltage transformer.

0Ω or
infinite

Shorted or open
winding

Defective high
voltage transformer

Approx
90-120Ω
(normal)

Disconnect one
side of the lead
wire connected
from transformer
to the high voltage
capacitor and
operate the unit.

0Ω or
infinite

Shorted or open
winding

Defective high
voltage transformer

15A fuse
again blows

Defective high
voltage capacitor

Replace

(Replace 15A fuse)

NOTE 1

Replace Primary
Interlock Switch
and Secondary
Interlock Switch
and monitor
Interlock Switch

NOTE 1

NOTE 1: All these switches must be replaced at the same time, please refer to page 22 and 23 for

adjustment instructions.

38

Condition

Check

CauseResult Remedy

Outlet has
proper
Voltage
Fuse does
not open

Check continuity
of open
thermostat

No
Continuity

Defective oven
thermostat

Replace

Check continuity
of power supply
cord.

No
Continuity

Open power
supply cord

Replace

Normal

Defective touch
control circuit

Replace

Malfunction of
secondary
interlock switch

Replace

Display do not
shown countdown

Condition

Check

CauseResult Remedy

Turn table
motor
fan moter and
oven lamp do
not turn on

Check continuity
of primary
interlock switch

No
Continuity

Malfunction of
Primary interlock
switch

Adjust or
replace

Approx.
24VDC

Faulty contacts
of RELAY "2"
coil

Replace

Defective touch
control circuit

Replace

Check D.C. voltage
being supplied to
RELAY "2" coil.

0V

(TROUBLE 4) Display shows all figures selected, but oven does not start cooking, even though

desired program and time and set and start pad is tapped.

39

Condition

Check

CauseResult Remedy

Check continuity
of primary winding
of high voltage
transformer and
touch control
circuit

Turn table motor
fan motor and
oven lamp turn
on for a
second when
the start pad
is tapped

No
Continuity

Normal

Open winding

Defective touch
control circuit

Replace

Replace

Replace

Replace

No microwave
oscillation

Check continuity
of connecting wire
of magnetron.

Continuity

Check the isolation
of filament winding
transformer

No
Good

Good

Defective
high voltage
transformer

Defective
magnetron

No
Continuity

No
Continuity

Defective
magnetron

Replace

Replace

Defective
high voltage
transformer

No
Continuity

Continuity

Continuity

Continuity
in the
reverse
direction

Defective
high voltage
diode

Replace

Check continuity
of filament of
magnetron.

Check continuity
of filament terminal
of high voltage
transformer

Check the diode
for continuity
and normal
directions

Condition

Check

CauseResult Remedy

(TROUBLE 5) No microwave oscillation even though fan motor rotates.

40

(TROUBLE 6) Microwave Output power is low .

First of all, check if output power is really low following "measurement of the microwave
output power" on page 24.

Output
power is low.

Check the power
source voltage
with magnetron
oscillating

Lower than
105 volts

Normal

Decrease in
power source
voltage

Customer
education

Check the timing
periods of the
RELAY "1" coil

NOTE 2

Defective touch
control circuit

Replace

Aging change
of
magnetron

Replace depending
on the result of
output test

Abnormal
NOTE 3

Condition Check CauseResult Remedy

Normal

41

1. High voltage is present at the high voltage terminal of the high voltage transformer during any cooking
cycle.

2. It is neither necessary nor advisable to attempt measurement of the high voltage.

3. Before touching any oven components or wiring, always unplug the oven from its power source and
discharge the capacitor (see page 28).

1. High voltage transformer

(A) Remove connections from the transformer

terminals and check continuity.

(B) Normal readings should be as follows:

Secondary winding.............Approx. 135Ω±10%

Filament winding...............................Approx. 0Ω

Primary winding.................................Approx. 0Ω

2. High voltage capacitor

(A) Check continuity of capacitor with meter on the

highest OHM scale.

(B) A normal capacitor will show continuity for a

short time, and then indicate 9MΩ once the

capacitor is charged.
(C) A shorted capacitor will show constant 9MΩ.
(D) An open capacitor will show constant 9MΩ.
(E) Resistance between each terminal and chassis

should be infinite.

3. High voltage diode

(A) Isolate the diode from the circuit by

disconnecting the leads.
(B) With the ohmmeter set on the highest

resistance scale, measure the resistance

across the diode terminals.

Reverse the meter leads and again observe the

resistance reading. Meter with 6V, 9V or higher

voltage batteries should be used to check the

front-back resistance of the diode, otherwise

an infinite resistance may be read in both

directions. A normal diodes resistance will be

infinite in one direction and several hundred KΩ

in the other direction.

4. Magnetron

For complete magnetron diagnosis, refer to
"Measurement of the Microwave Output
Power". (Page 24) Continuity checks can only
indicate and open filament or a shorted
magnetron. To diagnose for an open filament or
shorted magnetron.

(A) Isolate magnetron from the circuit by

disconecting the leads.

(B) A continuity check across magnetron filament

terminals should indicate ohm or less.

(C) A continuity check between each filament

terminal and magnetron case should read
open.

5. Fuse

If the fuse in the primary monitor switch circuit is
blown when the door is opened, check the
primary interlock switch and monitor switch
before replacing the blown fuse. In case the fuse
is blown by an improper switch operation,
replace the defective switch and fuse at the
same time. Replace just the fuse if the switches
operate normally .

COMPONENT TEST PROCEDURE

CAUTION: REPLACE BLOWN FUSE WITH

15 AMPERE FUSE.

42

6. Interlock switches

• You can test continuity of safety interlock and monitor switch by using ohmmeter.

• The switch operation is checked by zero/unlimited.
The meter should indicate zero resistance.

• The sequence of check is interlock monitor switch, primary and secondary interlock switches check.

1) In case of interlock monitor switch check.
Condition

1) Door is opened.

2) Common terminal of the monitor
switch disconnected.

2) In case of primary interlock switch check.
Condition

1) Door is closed.

PRIMARY
INTERLOCK SWITCH

INTERLOCK
MONITOR
SWITCH

POWER
SUPPLY
CORD

OHMMETER

PRIMARY
INTERLOCK SWITCH

INTERLOCK
MONITOR
SWITCH

POWER
SUPPLY
CORD

OHMMETER

1. CIRCUIT CHECK PROCEDURE

1) Low Voltage Transformer (DMR-604P) Check.

The low voltage transformer is located on the P.C.B.
Measuring condition: Input voltage: 120V

Frequency: 60Hz

2) Voltage Check

Key check point

CHECK METHOD

43

PRINTED CIRCUIT BOARD

NOTE 1: Secondary side voltage of the low voltage transformer changes in proportion to fluctuation

of power source voltage.

NOTE 2: The allowable tolerance of the secondary voltage is within ±5% of norminal voltage.

NOTE : Each measure point must be measured with GND points.

1

2

10

8
7

6

NO.

MEASURE POINT

WA VE FORM REMEDY REMARK

1 MP1 DC –5V ± 0.25 Replace ZD2, EC1, EC2 NO LOAD
2 MP2 DC –30V ± 1.0 Replace R21, ZD3 NO LOAD
3 MP3 DC –27V ± 1.0 Replace R21, R22, EC5 NO LOAD

T

0V

-14V

T: 16.67 ms (60 Hz)

T

0V

-5V
T: 250ns

NO. CHECK POINT REMARK

1 IC1 PIN 6, 10, 11 –5VDC
2 IC1 PIN 1 –30VDC

3 IC1 PIN 22

4 IC1 PIN 8 or 9

5 DP1 PIN 1 & 25 2.4 VAC (DISPLAY FILAMENT VOLTAGE)

Voltage

Terminal

LOAD NO LOAD

6–7 24V 30V

8–10 2.4V 2.5V

3) Display problems

44

DISPLA Y NAME MICOM OUTPUT

TROUBLE

& PIN NO. IN PIN NO.
DEFROST does’t come on. GRID 2 (G2), 17 29
COOK doesn’t come on. GRID 4 (G4), 10 28
SEGMENT "a" doesn't come on from G1 to G5. SEGMENT d, 19 39
SEGMENT "b" doesn't come on from G1 to G5. SEGMENT e, 18 40
SEGMENT "c" doesn't come on from G1 to G5. SEGMENT f, 16 41
SEGMENT "d" doesn't come on from G1 to G5. SEGMENT a, 23 36
SEGMENT "e" doesn't come on from G1 to G5. SEGMENT b, 22 37
SEGMENT "f" doesn't come on from G1 to G5. SEGMENT c, 20 38
SEGMENT "g" doesn't come on from G1 to G5. SEGMENT g, 15 42
DEFROST, COOK don't come on. UPPER BAR h, 5 33

R15

RY2

D10

A

Q5

19

+

R18

-

EC3

IC1

EC4

+

-

-24V

Q4

R13

RELAY "2"

NO. CAUSE MEASUREMENT RESUL T REMEDY

1 Poor contact between Check the voltage Fix the PIN 1 & 25

P.C.B. and display of PIN 1 & PIN 25. 2.4 VAC
filament.

2 Defective Display Refer to "The display Replace P.C.B.

trouble shooting data" assembly .
below.

3 Loss of vaccum in white spot White Replace P.C.B.

the display . spot is assembly

generated
on the
display

The display trouble shooting data

4) When there is no microwave oscillation.

(1) When touching "ST AR T" pad, oven lamp does not turn on.

Fan motor and turnatable motor do not rotate, but cook indicator in display comes on.
* Cause: RELA Y "2" does not operate.

45

Fig 9. Measurement Point

46

CHECK METHOD

(2) When touching "ST AR T" pad, oven lamp turns on.

Fan motor and turntable rotate and cook indicator in display comes on.
* Cause: RELA Y"1" does not operate.

CHECK METHOD

5) When the door is opened during operation, the count down timer does not stop.

CHECK METHOD

R10

RY1

D9

B

Q3

18

IC1

A

B

C2

IC1

16

-5V

R8

R9 D6

SECONDARY
INTERLOCK
SWITCH

CN1

A

POINT

A

ST AGE
RELA Y "2" ON –24VDC

RELA Y "2" OFF GND

POINT

AB

ST AGE
RELA Y "1" ON –5VDC GND

RELA Y "1" OFF GND GND

POINT

AB

ST AGE
RELA Y "1" ON –5VDC GND

RELA Y "1" OFF GND GND

CHECK

METHOD REMEDY

NO.

1 Check the stage (ON, OFF) of the secondary Replace secondary

Interlock switch by resistance measurement. interlock switch

6) When the digital clock does not operate properly

If clock does not keep exact time, you must check resistor R11, R17.

47

22

IC1

A

C4R11

R17

D13

D14

D11

D12

POINT WA VEFORM

A

OV

-14V

T: 16.67 ms

48

2. P. C. B. CIRCUIT DIAGRAM (MFM-6D)

2. P. C. B. CIRCUIT DIAGRAM (MFM-7DTP)

49

50

3. COMPONENT INFORMA TION

1) T ransistor

2) Diode and Zener Diode

Emitter Collector Base

Q1-5

DIODE Cathode (K)

ZENER
DIODE

Cathode (K)

ANODE (A) D1-7, 8-14

ANODE (A) ZD1-3

51

4. PRINTED CIRCUIT BOARD

52

5. P. C. B. LOCATION NO.

NO PART NAME RER NO. SPECIFICA TION P AR T CODE Q'TY REMARK

1 RESISTOR R10,12,13,18 4.7KΩ, 1/6W, 5% RD-AZ472J- 4
2 RESISTOR R3 200Ω, 1/6W, 5% RD-AZ201J- 1
3 RESISTOR R5,8 20KΩ, 1/6W, 5% RD-AZ203J- 2
4 RESISTOR R1 1MΩ, 1/6W, 5% RD-AZ105J- 1
5 RESISTOR R2,4,6,9,15,20 1KΩ, 1/6W, 5% RD-AZ102J- 6
6 RESISTOR R11,17 47KΩ, 1/6W , 5% RD-AZ473J- 2
7 RESISTOR R24 51Ω, 1/4W, 5% RD-AZ510J- 1
8 RESISTOR R22,25 56Ω, 1/2W , 5% RD-2Z560JS 2

9 RESISTOR R14,19,23 200Ω, 1/2W, 5% RD-2Z122JS 1
10 DIODE SWITCHING R21 1.2KΩ, 1/2W, 5% RD-2Z122JS 1
11 DIODE RECTIFYING D1-7 1N4148M DZN4148M-- 7
12 DIODE RECTIFYING D8-14 1N4002A DZN4002A-- 7
13 DIODE ZENER ZD1 3.9VB, 1/2W DZTZ3R9B-- 1
14 DIODE ZENER ZD2 5.1VB, 1/2W DZTZ5R1B--- 1
15 DIODE ZENER ZD3 20VB, 1/2W DZTZ20B--- 1
16 TRANSISTOR Q5 KTC3198GR TZTC3198GR 1
17 TRANSISTOR Q1-4 KTA1270Y TZT A1270Y- 4
18 RESISTOR ARRA Y RA1 RGLD6X104J RA-87X104J 1
19 CAP ACITOR CERAMIC C4 HIKF 50V 0.01uF Z CCXF1H103Z 1
20 CAP ACITOR CERAMIC C1-3 HIKF 50V 0.1uF Z CBXF1H104Z 3
21 CAP ACITOR ELECTROLYTIC EC5 220uF, 50V , RSS CEXF1H471V 1
22 CAP ACITOR ELECTROLYTIC EC1-2 47uF, 16V , RS CEXF1C470A 2
23 CAP ACITOR ELECTROLYTIC EC3 0.1uF, 50V , RS CEXE1H108A 1
24 CAP ACITOR ELECTROLYTIC EC4 2.2uF, 50V , RS CEXE1H229A 1
25 CAP ACITOR ARRAY CA1 1000pF 2.54mm M50V CN6XB-102M 1
26 BUZZER BZ1 BM-20K 3515600100 1
27 RESONATOR CR1 KBR-4.0 MKSTF 5PKBR 40MKS 1
28 CONNECTOR FILM CN2 FCZ 254-11 (YEONHO) 441M367160 1
29 CONNECTOR WAFER CN3 YW396-05VA 3519150510 1
30 CONNECTOR WAFER CN1 YW396-02V 3519150520 1
31 DIGITRON DP1 SVM-5MS06 DSVM5MS06-1 1
32 HOLDER VFD HD1 NYLON66 351300500 1
33 PCB MAIN M145 M145-1 3514311351 1
34 TRANS POWER L VT1 DMR-604P 5EPU041403 1
35 RELA Y RY1,3 G5J-1-TP-M24V 5SC0101107 2
36 RELA Y RY2 G5B-1 (DC24V) 5SC0101109 1
37 IC MICOM IC1 HD404314B47S 147S811F00 1

MFM-6D

HD404314D13S 147S818F00 1

MFM-7DTP

1. Door Assembly

53

EXPLODED AND P AR TS LIST

A01

A02

A04

A03

A06

A05

A07

A08

REF. NO P ART CODE PART NAME DESCRIPTION Q'TY REMARK

A01 3517003100 BARRIER-SCREEN *0 PMMA T0.5 1
A02 3512202200 FRAME DOOR ABS HR-401 H-2938 1
A03 3515201500 STOPPER HINGE *T AS KOR-61150S 1
A04 3511706520 DOOR PAINTING AS KOR-81250S 1
A05 3517002900 BARRIER-SCREEN *I POL YESTER T0.1 1
A06 3512300400 GASKET DOOR PP 1
A07 3513100700 HOOK POM 1
A08 3515101300 SPRING HOOK PW1 1

DOOR ASSEMBLY : 3511706402

54

2. Control Panel Assembly

B01

B02

B03

B04

B05

B06

B07

REF. NO P ART CODE P ART NAME DESCRIPTION Q'TY REMARK

B01

3518517540

SWITCH MEMBRANE

KOR-811F2A

1

MFM-6D

3518517550 KOR-811F3A MFM-7DTP

B02 3516713410 CONTROL-P ANEL ABS AF-345 HF-700HT 1
B03

PKMPMSR100

PCB MAIN AS

KOR-811F2A

1

MFM-6D

PKMPMSWK00 KOR-811F 3A MFM-7DTP
B04 7122401211 SCREW TAPPING T2S TRS 4X12 MFZN 4
B05 3513702500 LEVER DOOR OPEN POM 1
B06 441G430171 SPRING DOOR BUTTON SWP DIA. 0.7 1
B07 3516904410 BUTTON DOOR OPEN ABS AF-345 HF-700HT 1

CONTROL P ANEL ASSEMBLY: PKCPSWR100 (MFM-6D)

PKCPSWWK00 (MFM-7DTP

55

56

REF. NO P AR T CODE PAR T NAME DESCRIPTION Q'TY REMARK

A00 DOOR AS See Exploded and Part List 1

B00 CONTROL-PANEL AS 1

F01 3510801400 CABINET PCM T0.6 1
F02 7112401011 SCREW TAPPING T1 TRS 4x10 MFZN 3
F03 3516105640 CA VITY AS KOR-811F2A 1
F04 7122401211 SCREW TAPPING T2S TRS 4x12 MFZN 2
F05 7122401211 SCREW TAPPING T2S TRS 4x12 MFZN 1
F06 4413A90012 CLAMP POWER CORD NYLON 66 1
F07 7112401011 SCREW TAPPING T1 TRS 4x10 MFZN 2
F08 35113NBNQ5 CORD POWER AS 3x0.75 60x60 160-RTML 1
F09 3519101400 CONN OUTLET AC0709-PQ 1
F10 3518002200 MAGNETRON 2M218H (MF) I 1
F11 3516002700 SCREW SPECIAL T2S FG HEX 4X13 MFZN 3
F12 7112401011 SCREW SPECIAL T1 TRS 4x10 MFZN 2
F13 7S101W4081 SCREW MACHINE PAN FLANGE 4x8 MFZN 2
F14 3511402500 COVER *B SBHG T0.8 1
F15 3963820110 MOTOR SHADED POLE 120V 17W MW10XA-R01 1
F16 3511800300 FAN PP+30% GLASS 1
F17 7272400811 SCREW TAPTITE TT3 TRS 4x8 MFZN 1
F18 3513001900 HOLDER HV CAPACITOR SECC T0.8 1
F19 441L267010 CAPACITOR HV 2100VAC 0.07uF 1
F20 4416V24000 DIODE HV SANKEN HVR-1X-32B (D5.3) 1
F21 3518111700 TRANS HV JMOT-N60A0-81T 1
F22 3516003700 SCREW SPECIAL TT3 HEX FG 4x8 MFZN 4
F23 3512100900 FOOT PP DASF-130 2
F24 3510308900 BASE SBHG T0.8 1
F25 7272400811 SCREW TAPTITE TT3 TRS 4x8 MFZN 2
F26 7112401011 SCREW TAPPING T1 TRS 4x10 MFZN 6
F27 3512201100 STOPPER HINGE *U SCP-1 T2.5 1
F28 4415A17352 SW MICRO

VP-533A-OF SPNO #187 200G

1

F29 4415A66600 SW MICRO

VP-523A-OF SPNO #187 200G

1

F30 4415A17352 SW MICRO

VP-533A-OF SPNO #187 200G

1
F31 3513701300 LEVER LOCK POM 1
F32 3513805700 LOCK POM 1
F33 3513601500 LAMP BL 125V 25W T25 C5A H187 1
F34 7121400611 SCREW TAPPING T2S PAN 4x6 MFZN 2
F35 3966820200 MOTOR SYNCRO 120V 2W GM-16-12F17 1
F36 441X310012 COVER WAVE GUIDE PP 1
F37 3517400600 COUPLER PPS 1
F38 3514700900 ROLLER TEFLON 3
F39 3512509200 GUIDE ROLLER PP 1

F 3512510600 GUIDE ROLLER AS KOR-6115OS 1
F40 3517203500 TRAY GLASS 1
F41 3516003700 SCREW SPECIAL TT3 HEX FG 4x8 MFZN 2

DAEWOO ELECTRONICS CO., LTD.

S/M NO.: R821M AM012

686, AHYEON-DONG, MAPO-GU,
SEOUL, KOREA.
C.P.O. BOX 8003 SEOUL KOREA
TELEX: DWELEC K28177-8
FAX: [phone]
TEL: [phone]

PRINTED DATE: JUN. 1998