JVC AV-27F702/S Service Manual

SERVICE MANUAL
COLOR TELEVISION
AV-27F702
BASIC CHASSIS
AC
AV-27F702
CD-ROM No. SML200102
/S
CONTENTS
a SPECIFICATIONS ....................................................................................................................................2
a SAFETY PRECAUTIONS ........................................................................................................................3
a FEATURES ..............................................................................................................................................4
a FUNCTIONS .............................................................................................................................................5
a SPECIFIC SERVICE INSTRUCTIONS ....................................................................................................6
a SERVICE ADJUSTMENTS ....................................................................................................................11
¤ STANDARD CIRCUIT DIAGRAM (APPENDIX) .................................................................................. 2-1
a PARTS LIST ...........................................................................................................................................29
COPYRIGHT © 2001 VICTOR COMPANY OF JAPAN, LTD.
No. 51786
Jan. 2001
AV-27F702

SPECIFICATIONS

Items Contents
Dimensions (W × H × D)
················································································································································································································
Mass
················································································································································································································
TV RF System
················································································································································································································
Color Sound System
················································································································································································································
TV Receiving Channels and Frequency
VL Band
VH Band
UHF Band
················································································································································································································
CATV Receiving Channels and Frequency
Low Band
High Band
Mid Band
Super Band
Hyper Band
Ultra Band
Sub Mid Band
TV/CATV Total Channel
················································································································································································································
Intermediate Frequency
Video IF Carrier
Sound IF Carrier
Color Sub Carrier
················································································································································································································
Power Input
Power Consumption
················································································································································································································
Picture Tube
High Voltage
················································································································································································································
Speaker
Audio Power Output
················································································································································································································
Video / Audio Input (1 / 2 / 3)
29-7/8” × 23-3/8” × 19-3/4” / 75.8cm × 59.3cm × 50.0cm
101.2 lbs / 46 kg
CCIR(M)
NTSC, BTSC System (Multi Channel Sound)
(02~06) 54MHz~88MHz
~13) 174MHz~216MHz
(07
(14
~69) 470MHz~806MHz
(02~06, A-8) by (02~06&01)
(07~13) by (07~13)
(A~1) by (14~22)
(J~W) by (23~36) (54MHz~804MHz)
(W+1~W+28) by (37~64)
(W+29~W+84) by (65~125)
(A8, A4~A1) by (01, 96~99)
180 Channels
45.75MHz
41.25MHz (4.5MHz)
3.58MHz
120V AC, 60Hz
140W / 2.0A
27” (68cm) Measured Diagonally
30kV±1kV (at zero beam current)
2” × 4-3/4” / 5 × 12cm Oval type × 2
5W × 2
Video(1,2,3) : 1Vp-p, 75Ø (RCA pin jack)
Audio(1,2,3) : 500mVrms ( -4dBs ), High Impedance (RCA pin jack)
S-Video ( Input 1 / 3 Over )
Y : 1Vp-p Positive (negative sync provided, when terminated with 75Ø)
C : 0.286Vp-p (burst signal, when terminated with 75Ø)
Component Input ( Input 2 )
Y : 1Vp-p positive (negative sync provided, when terminated with 75Ø)
PB/PR : 0.7Vp-p 75 Ø
················································································································································································································
Audio Output
(Variable / Fix : Selectable)
················································································································································································································
AV Compu link EX Input
················································································································································································································
Antenna terminal
················································································································································································································
Remote Control Unit
Variable : More then 0~1550mVrms (+6dBs)
Low impedance (400Hz when modulated 100%)
Fix : 500mVrms(-4dBs)
Low impedance (400Hz when modulated 100%)
3.5mm mini jack
75Ø(VHF/UHF) Terminal, F-Type Connector
RM-C303G-1A
(AA/R6/UM-3 battery × 2)
(RCA pin jack)
(RCA pin jack)
Design & specifications are subject to change without notice.
2 No. 51786
GOOD EARTH GROUND
0.15 µF AC-TYPE
AC VOLTMETER (HAVING 1000Ø/V, OR MORE SENSITIVITY)
PLACE THIS PROBE ON EACH EXPOSED METAL PART
1500Ø 10W
A V
This mark shows a fast
POWER CORD REPLACEMENT WARNING
Connecting thr white line side of power cord to “WHT” character side.
operating fuse, the letters indicated below show the rating.
PWB
WHT
PW
White line side

SAFETY PRECAUTIONS

1. The design of this product contains special hardware, many circuits and components specially for safety purposes. For continued pro­tection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Service should be performed by qualified personnel only.
2. Alterations of the design or circuitry of the products should not be made. Any design alterations or additions will void the manufactur­er's warranty and will further relieve the manufacturer of responsi­bility for personal injury or property damage resulting therefrom.
3. Many electrical and mechanical parts in the products have special safety-related characteristics. These characteristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in the parts list of Service manual. Electrical components having such features are
identified by shading on the schematics and by ( ) on the parts list in Service manual. The use of a substitute replacement
which does not have the same safety characteristics as the recom­mended replacement part shown in the parts list of Service manual may cause shock, fire, or other hazards.
4. Use isolation transformer when hot chassis. The chassis and any sub-chassis contained in some products are connected to one side of the AC power line. An isolation transformer of adequate capacity should be inserted between the product and the AC power supply point while performing any service on some products when the HOT chassis is exposed.
5. Don't short between the LIVE side ground and ISOLATED (NEU-
TRAL) side ground or EARTH side ground when repairing.
Some model's power circuit is partly different in the GND. The dif­ference of the GND is shown by the LIVE : ( ) side GND, the ISOLATED(NEUTRAL) : ( ) side GND and EARTH : ( ) side GND. Don't short between the LIVE side GND and ISOLATED(NEUTRAL) side GND or EARTH side GND and never measure with a measuring apparatus (oscilloscope etc.) the LIVE side GND and ISOLATED(NEUTRAL) side GND or EARTH side GND at the same time. If above note will not be kept, a fuse or any parts will be broken.
6. If any repair has been made to the chassis, it is recommended that the B1 setting should be checked or adjusted (See ADJUSTMENT OF B1 POWER SUPPLY).
7. The high voltage applied to the picture tube must conform with that specified in Service manual. Excessive high voltage can cause an increase in X-Ray emission, arcing and possible component dam­age, therefore operation under excessive high voltage conditions should be kept to a minimum, or should be prevented. If severe arcing occurs, remove the AC power immediately and determine the cause by visual inspection (incorrect installation, cracked or melted high voltage harness, poor soldering, etc.). To maintain the proper minimum level of soft X-Ray emission, components in the high voltage circuitry including the picture tube must be the exact replacements or alternatives approved by the manufacturer of the complete product.
8. Do not check high voltage by drawing an arc. Use a high voltage meter or a high voltage probe with a VTVM. Discharge the picture tube before attempting meter connection, by connecting a clip lead to the ground frame and connecting the other end of the lead through a 10kØ 2W resistor to the anode button.
9. When service is required, observe the original lead dress. Extra precaution should be given to assure correct lead dress in the high voltage circuit area. Where a short circuit has occurred, those com­ponents that indicate evidence of overheating should be replaced. Always use the manufacturer's replacement components.
No. 51786 3
AV-27F702
10. Isolation Check
(Safety for Electrical Shock Hazard)
After re-assembling the product, always perform an isolation check on the exposed metal parts of the cabinet (antenna terminals, video/ audio input and output terminals, Control knobs, metal cabinet, screwheads, earphone jack, control shafts, etc.) to be sure the prod­uct is safe to operate without danger of electrical shock.
(1) Dielectric Strength Test
The isolation between the AC primary circuit and all metal parts exposed to the user, particularly any exposed metal part having a return path to the chassis should withstand a voltage of 1100V AC (r.m.s.) for a period of one second.
(. . . . Withstand a voltage of 1100V AC (r.m.s.) to an appliance rated
up to 120V, and 3000V AC (r.m.s.) to an appliance rated 200V or more, for a period of one second.) This method of test requires a test equipment not generally found in the service trade.
(2) Leakage Current Check
Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Using a Leakage Current Tester, measure the leakage current from each exposed metal part of the cabinet, particularly any exposed metal part having a return path to the chassis, to a known good earth ground (water pipe, etc.). Any leakage current must not exceed 0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.2mA AC (r.m.s.).
Alternate Check Method
Plug the AC line cord directly into the AC outlet (do not use a line isolation transformer during this check.). Use an AC voltmeter hav­ing 1000 ohms per volt or more sensitivity in the following manner. Connect a 1500Ø 10W resistor paralleled by a 0.15µF AC-type ca­pacitor between an exposed metal part and a known good earth ground (water pipe, etc.). Measure the AC voltage across the resis­tor with the AC voltmeter. Move the resistor connection to each ex­posed metal part, particularly any exposed metal part having a re­turn path to the chassis, and measure the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. Any voltage measured must not exceed 0.75V AC (r.m.s.). This corresponds to 0.5mA AC (r.m.s.). However, in tropical area, this must not exceed 0.3V AC (r.m.s.). This corresponds to 0.2mA AC (r.m.s.).
11 . High voltage hold down circuit check.
After repair of the high voltage hold down circuit, this circuit shall be checked to operate correctly. See item “How to check the high voltage hold down circuit”.
AV-27F702

FEATURES

Full-flat CRT (cathode ray tube) reproduces fine textured picture in
every detail. I2C bus control utilizes single chip ICs.
Built-in HYPER-SURROUND system.
Built-in BBE.
3 LINE DIGITAL COMB FILTER circuit improved picture quality.
Component input terminal for talking best advantage of Component
Video Signal.
a SYSTEM BLOCK DIAGRAM
IC702
E2PROM 4k bit
SCL 1 SDA 1
Audio Video input terminal. (S-input ×2, V-input ×3)
Variable/Fix audio output terminal.
Closed-caption broadcasts can be viewed.
With AV COMPU LINK EX terminal.
Remote
control
unit
SCL 0 SDA 0
IC701
MAIN MICON
IC101
1 CHIP
CONTROL
AFC
IC501
AVSW
CONTROL
TU001
TUNER
IC001
MTS, TONE
SURROUND CONTROL
4 No. 51786

FUNCTIONS

a FRONT PANEL
AV-27F702
a FRONT PANEL DOOR OPENED
a REAR PANEL
a REMOTE CONTROL UNIT
(RM-C303G-1A)
2
No. 51786 5
AV-27F702

SPECIFIC SERVICE INSTRUCTIONS

DISASSEMBLY PROCEDURE
REMOVING THE REAR COVER
1. Unplug the power supply cord.
2. Remove the 12 screws marked A as shown in Fig.1.
3. Withdraw the REAR COVER toward you.
[CAUTION]
When reinstalling the rear cover, carefully push it inward after in-
serting the MAIN PWB into the rear cover groove.
REMOVING THE CHASSIS
After removing the rear cover.
1. Slightly raise the both sides of the chassis by hand and remove the 3 claws marked B under the chassis from the front cabinet as shown in Fig.1.
2. Withdraw the chassis backward along the rail in the arrow direction marked C as shown in Fig.1.
(If necessary, take off the wire clamp, connectors etc.)
When conducting a check with power supplied, be sure to confirm
*
that the CRT earth wire is connected to the CRT SOCKET PWB and the MAIN PWB.
REMOVING THE TERMINAL BOARD
After removing the rear cover.
1. Remove the 6 screws marked D as shown in Fig.1.
2. When you pull out the TERMINAL BOARD in the direction of arrow marked E as shown in Fig.1, it can be removed.
REMOVING THE DAF PW BOARD
After removing the rear cover and chassis.
1. Lift the right side of the DAF PWB while pressing the PWB stopper marked J and claw marked K in the arrow direction marked L as shown in Fig.1.
2. Then remove the DAF PWB.
(If necessary, take off the wire, connectors etc.)
REMOVING THE SPEAKER
After removing the rear cover.
1. Remove the 4 screws marked M as shown in Fig.1.
2. Withdraw the speaker backward.
3. Follow the same steps when removing the other hand speaker.
CHECKING THE MAIN PW BOARD
1. To check the back side of the MAIN PW Board.
1) Pull out the chassis. (Refer to REMOVING THE CHASSIS).
2) Erect the chassis vertically so that you can easily check the back
side of the MAIN PW Board.
[CAUTION]
When erecting the chassis, be careful so that there will be no con-
tacting with other PW Board. Before turning on power, make sure that the CRT earth wire and
other connectors are properly connected.
REMOVING THE FRONT AND POWER SW PW BOARDS
After removing the rear cover and chassis.
1. Remove the 4 screws marked F as shown in Fig.1.
2. Then remove the FRONT PWB and POWER SW PWB.
(If necessary, take off the wire, connectors etc.)
REMOVING THE LF PW BOARD
After removing the rear cover and chassis.
1. Lift the left side of the LF PWB while pressing the 2 PWB stoppers marked G in the arrow direction marked H as shown in Fig.1.
2. Then remove the LF PWB.
(If necessary, take off the wire, connectors etc.)
WIRE CLAMPING AND CABLE TYING
1. Be sure clamp the wire.
2. Never remove the cable tie used for tying the wires together. Should it be inadvertently removed, be sure to tie the wires with a new cable tie.
6 No. 51786
FRONT CABINET
AV-27F702
SPEAKER
M
(x4)
CRT SOCKET PWB
REAR COVER
POWER SW PWB
CLAW
B
PWB STOPPER
G
FRONT PWB
H
LF PWB
F
(x4)
CLAW
PWB
G
STOPPER
CLAW
K
DAF PWB
L
B
C
PWB STOPPER
J
CHASSIS
MAIN PWB
E
D
(x6)
A
(x12)
Fig.1
No. 51786 7
AV-27F702
MEMORY IC REPLACEMENT
1. Memory IC
This model use a memory IC. This memory IC stores data for proper operation of the video and deflection circuits. When replacing, be sure to use an IC containing this (initial value) data.
2. Memory IC replacement procedure
Procedure Screen display
(1) Power off
Switch off the power and disconnect the power cord from the outlet.
(2) Replace the memory IC
Initial value must be entered into the new IC.
(3) Power on
Connect the power cord to the outlet and switch on the power.
(4) System constant check and setting
1) Press SLEEP TIMER key and, while the indication of “SLEEP TIMER 0 MIN. is being displayed, press DISPLAY key and VIDEO STATUS
key on the remote control unit simultaneously.
2) The SERVICE MENU screen of Fig.1 is displayed.
3) While the SERVICE MENU is displayed, again simultaneously press the DISPLAY and VIDEO STATUS keys to display the Fig.2 SYSTEM CONSTANT screen.
4) Refer to the SYSTEM CONSTANT table and check the setting items. Where these differ, select the setting item with the MENU UP/DOWN key and adjust the setting with the MENU LEFT/RIGHT keys. (The letters of the selected item are displayed in yellow.)
5) After adjusting, release the MENU LEFT/RIGHT key to store the setting value.
6) Press the EXIT key twice to return the normal screen.
(5) Receive channel setting
Refer to the OPERATING INSTRUCTIONS(USER'S GUIDE) and set the receive channels (Channels Preset) as described.
(6) User settings
Check the user setting items according to Table 2. Where these do not agree, refer to the OPERATING INSTRUCTIONS (US­ER'S GUIDE) and set the items as described.
SERVICE MENU
PICTURE SOUND THEATER OTHERS
LOW LIGHT HIGH LIGHT RF AFC VCO(CW) I2C BUS CTRL
SELECT BY OPERATE BY
Fig.1
SYSTEM CONSTANT
MODEL :99– TM CORR. : NO CCD : YES V-CHIP : YES CAN V-CHIP : NO
EXIT BY
99999
999999999 999
SELECT BY OPERATE BY
Fig.2
EXIT BY
EX
IT
EX
IT
(7) SERVICE MENU setting
Verify what to set in the SERVICE MENU, and set whatever is necessary.(Fig.1) Refer to the SERVICE ADJUSTMENT for setting.
8 No. 51786
AV-27F702
TABLE 1 (System Constant setting)
Setting item Setting content Setting value
AV-27F802 AV-32F802 AV-36F802 AV-27F702 AV-32F702
MODEL AV-27F702
AV-36D502 AV-32D502 AV-27D502 AV-36F702
AV-32D302 AV-36D302 AV-32D202 AV-36D202
AV-36230 AV-32230 AV-36260 AV-32260 AV-27260
TM CORR.
CCD
V-CHIP
CAN V-CHIP
YES NO
YES NO
YES NO
YES NO
TABLE 2 (User setting value)
Setting item Setting value
1. Use remote controller keys
POWER OFF CHANNEL CH-02 VOLUME 05 INPUT TV HYPER SURROUND OFF BBE ON DISPLAY OFF SLEEP TIMER 0 VIDEO STATUS CHOICE
2. Setting of MENU
PICTURE ADJUST
TINT CENTER COLOR CENTER PICTURE CENTER BRIGHT CENTER DETAIL CENTER NOISE MUTING ON SET VIDEO STATUS ALL CENTER
NO
YES
YES
NO
SOUND ADJUST
BASS CENTER TREBLE CENTER BALANCE CENTER MTS STEREO
CLOCK/TIMERS
SET CLOCK Unnecessary to set ON/OFF TIMER NO
INITIAL SETUP
TV SPEAKER ON AUDIO OUT FIX COMPONENT-IN NO LANGUAGE ENG CLOSED CAPTION OFF AUTO TUNER SETUP Unnecessary to set CHANNEL SUMMARY Unnecessary to set V-CHIP OFF SET LOCK CODE Unnecessary to set
No. 51786 9
AV-27F702
REPLACEMENT OF CHIP COMPONENT
CAUTIONS
a
1. Avoid heating for more than 3 seconds.
2. Do not rub the electrodes and the resist parts of the pattern.
3. When removing a chip part, melt the solder adequately.
4. Do not reuse a chip part after removing it.
SOLDERING IRON
a
1. Use a high insulation soldering iron with a thin pointed end of it.
2. A 30w soldering iron is recommended for easily removing parts.
REPLACEMENT STEPS
a
1. How to remove Chip parts
Resistors, capacitors, etc.
(1) As shown in the figure, push the part with tweezers and alter-
nately melt the solder at each end.
2. How to install Chip parts
Resistors, capacitors, etc.
(1) Apply solder to the pattern as indicated in the figure.
(2) Shift with tweezers and remove the chip part.
Transistors, diodes, variable resistors, etc.
(1) Apply extra solder to each lead.
SOLDER
(2) As shown in the figure, push the part with tweezers and alter-
nately melt the solder at each lead. Shift and remove the chip part.
SOLDER
(2) Grasp the chip part with tweezers and place it on the solder.
Then heat and melt the solder at both ends of the chip part.
Transistors, diodes, variable resistors, etc. (1) Apply solder to the pattern as indicated in the figure. (2) Grasp the chip part with tweezers and place it on the solder. (3) First solder lead A as indicated in the figure.
A
B
C
(4) Then solder leads B and C.
A
Note : After removing the part, remove remaining solder from the
pattern.
10 No. 51786
B
C
AV-27F702

SERVICE ADJUSTMENTS

ADJUSTMENT PREPARATION:
1. You can make the necessary adjustments for this unit with either the remote control unit or with the adjustment equipment and parts as given below.
2. Adjustment with the remote control unit is made on the basis of the initial setting values, however, the new setting values which set the screen to its optimum condition may differ from the initial settings.
3. Make sure that AC power is turned on correctly.
4. Turn on the power for the set and test equipment before use, and start the adjustment procedures after waiting at least 30 minutes.
5. Unless otherwise specified, prepare the most suitable reception or input signal for adjustment.
6. Never touch any adjustment parts, which are not specified in the list for this adjustment-variable resistors, transformers, capacitors, etc.
7. Presetting before adjustment. Unless otherwise specified in the adjustment instructions, preset the following functions with the remote control unit.
User mode setting position
VIDEO STATUS STANDARD
HYPER SURROUND OFF
BASS, TREBLE, BALANCE CENTER
TINT, COLOR, PICTURE, BRIGHT, DETAIL
CENTER
MEASURING INSTRUMENT
1. DC voltmeter(or digital voltmeter)
2. Oscilloscope
3. Signal generator ( Pattern generator ) [NTSC]
4. Remote control unit
5. TV audio multiplex signal generator
6. Frequency counter
7. Resistor (1MØ)
ADJUSTMENT ITEMS
Check of B1 POWER SUPPLY
RF AGC adjustment
FOCUS adjustment
WHITE BALANCE adjustment
WHITE BALANCE (Low Light) adjustment WHITE BALANCE (High Light) adjustment
BRIGHT adjustment
SUB BRIGHT adjustment
CONTRAST adjustment
SUB CONTRAST adjustment
DEFLECTION adjustment
V.CENTER and TRAPEZIUM adjustment V-SIZE and V-LINEARITY adjustment H SIZE and H POSITION adjustment SIDE PIN and CORNER PIN adjustment
CHROMA adjustment
SUB COLOR adjustment SUB TINT adjustment
MTS circuit adjustment
INPUT LEVEL check STEREO VCO adjustment SAP VCO adjustment FILTER check SEPARATION adjustment
No. 51786 11
AV-27F702
ADJUSTMENT LOCATIONS
POWER SW PWB FRONT PWB
S706
S705 S703
B CN007
S701
D101
IC101
FRONT
S702S704
S702 : MENU S703 : CHANNEL–
CN006B
S704 : CHANNEL+ S705 : VOLUME– S706 : VOLUME+
LINE FILTER PWB
FRONT FRONT
P
E3
MAIN PWB
CN006
SS
IC701 CPU
CN007
P
DEG
IC702
DAF PWB
J601
CN004
MPX
HV
Q511 Heatsink
CP
R507
DAF
K
E1
Q
CN005
S1
C
F901 125V 5A
PW
E1
CN002 CN001
FRONT
Q
K
DAFCP
AV SW PWB
J501
J502
FRONT
TOP
CN001
CN002
J503
TU001
UPPER : H MIDDLE : FOCUS LOWER : SCREEN
CRT SOCKET PWB
TP-G
CN004
(SOLDER SIDE)
TP-E1
CN005
TOP
E2
12 No. 51786
BASIC OPERATION OF SERVICE MENU
1. TOOL OF SERVICE MENU OPERATION
Operate the SERVICE MENU with the REMOTE CONTROL UNIT.
2. SERVICE MENU ITEMS
In general, basic setting (adjustments) items or verifications are performed in the SERVICE MENU.
PICTURE ............................... This sets the setting values (adjustment values) of the VIDEO/CHROMA and DEFLECTION circuits.
SOUND .................................. This sets the setting values (adjustment values) of the AUDIO circuit.
THEATER .............................. This is used when the THEATER MODE is adjusted.
OTHERS ................................ This is used when the OTHERS MODE is adjustment.
LOW LIGHT ........................... This sets the setting values (adjustment values) of the WHITE BALANCE circuit.
HIGH LIGHT .......................... This sets the setting values (adjustment values) of the WHITE BALANCE circuit.
RF AFC .................................. This is used when the RF AFC MODE is verified. [Do not adjust]
VCO (CW) .............................. This is not used for service.
I2C BUS CTRL ...................... This is used when ON/OFF of the I2C BUS CTRL is set. [Fixed ON]
3. Basic Operations of the SERVICE MENU
(1) How to enter the SERVICE MENU.
Press SLEEP TIMER key and, while the indication of SLEEP TIMER 0 MIN.” is being displayed, press DISPLAY key and VIDEO STATUS key on the remote control unit simultaneously to enter the SERVICE MENU screen 1 shown in the next figure page.
AV-27F702
(2) SERVICE MENU screen selection
Press the UP / DOWN key of the MENU to select any of the following items. (The letters of the selected items are displayed in yellow.)
PICTURE
THEATER
LOW LIGHT
RF AFC
VCO(CW)
(3) Enter the any setting ( adjustment ) mode
PICTURE, SOUND and OTHERS mode
1) If select any of PICTURE, SOUND or OTHERS items, and the LEFT / RIGHT key is pressed from SERVICE MENU ( MAIN MENU ), the screen 2 will be displayed as shown in figure page later.
2) Then the UP / DOWN key is pressed, the PICTURE mode screen 3 or the SOUND mode screen 4 or the OTHER mode screen 5 is displayed, and the PICTURE, SOUND or OTHERS setting can be performed.
THEATER, LOW LIGHT, HIGH LIGHT, RF AFC, VCO(CW) and I2C BUS CTRL mode
1) If select any of THEATER / LOW LIGHT / HIGH LIGHT / RF AFC / VCO (CW) / I2C BUS CTRL items, and the LEFT / RIGHT key is pressed from SERVICE MENU ( MAIN MENU ), the screens 6 7 8 9 10 11 will be displayed as shown in figure page later.
2) Then the settings or verifications can be performed.
SOUND
OTHERS
HIGH LIGHT
I2C BUS CTRL
No. 51786 13
AV-27F702
1
SERVICE MENU (MAIN MENU) SCREEN PICTURE MODE
SERVICE MENU
PICTURE SOUND THEATER OTHERS
LOW LIGHT HIGH LIGHT RF AFC VCO(CW) I2C BUS CTRL
SELECT BY OPERATE BY
9
RF AFC MODE
EXIT BY
EX
IT
SELECT BY
1. NOISE DET. STAT US
[DO NOT ADJUST]
2
EX
EXIT BY
IT
4
SOUND MODE OTHERS MODE
999
99999999
6
THEATER MODE (1/2) THEATER MODE (2/2)
3
1. BRIGHT STAT US
5
1. OSD POS.
999
99999999
999
TOO HIGH GOOD TOO LOW
RF AFC ON FINE
SELECT BY OPERATE BY
10
VCO (CW) MODE
EXIT BY
999
EX
[DO NOT USE]
HIGH LEVEL REFERENCE LEVEL LOW LEVEL
SYNC : YES
11
I2C BUS CTRL MODE [FIXED ON]
TINT COLOR PICTURE BRIGHT DETAIL R CUT. G CUT.
SELECT BY
IT
OPERATE BY
BRIGHT
999 999 999 999 999 999 999
7
LOW LIGHT MODE
999
999 999
8
HIGH LIGHT MODE
B CUT. R DRIVE B DRIVE DC REST. BLK ST. GMM PNT
EXIT BY
999 999 999 999 999 999
PAGE 1/2
EX IT
999
CD MAT. RY GAIN GY PHASE CORING
SELECT BY OPERATE BY
99 99 99 99
CMP CD M CMP RY G CMP GY P CMP COR
EXIT BY
99 99 99 99
PAGE 2/2
EX
IT
I2C BUS ON
SELECT BY OPERATE BY
EXIT BY
EX
IT
HIGH LIGHT
999 999
14 No. 51786
(4) Setting method
1. BRIGHT STATUS
999
99999999
SETTING ITEM
INITIAL SETTING VALUE (Adjust) SETTING VALUE
PICTURE MODE
1) UP / DOWN key of the MENU Select the SETTING ITEM.
2) LEFT / RIGHT key of the MENU Setting (adjust) the SETTING VALUE of the SETTING ITEM. When the key is released the SETTING VALUE will be stored (memorized).
3) EXIT key Returns to the previous screen.
(5) Releasing SERVICE MENU
1) After returning to the SERVICE MENU upon completion of the setting (ad­justment) work, press the EXIT key again.
AV-27F702
¤ The settings for LOW LIGHT and HIGH LIGHT are described in the WHITE BAL-
ANCE page of ADJUSTMENT.
No. 51786 15
AV-27F702
INITIAL SETTING VALUE OF SERVICE MENU
1. Adjustment of the SERVICE MENU is made on the basis of the initial setting values; however, the new setting values which set the screen in its optimum condition may differ from the initial setting.
2. Do not change the initial setting values of the setting (Adjustment) items not listed in “ADJUSTMENT”.
PICTURE MODE
The four setting items in the video mode No.6 EXT BRI., No.7 EXT PIC., No.8 EXT COL. and No.9 EXT TINT are linked to the items in the TV MODE No.1 BRIGHT, No.2 PICTURE, No.3 COLOR and No.4 TINT, respectively. When the setting items in the TV mode are adjusted, the values in the setting items in the video mode are revised automatically to the same values in the TV mode.(The initial setting values given in ( ) are off-set values.) When the four items (No.6, 7, 8 and 9) are adjusted in the video mode, the setting values in each item are revised independently.
No. Setting (Adjustment) item Variable range Initial setting value
1 BRIGHT 000 127 063
2 PICTURE 000 127 070
3 COLOR 000 127 072
4 TINT 000 127 056
5 TV DETAIL 000 063 050
6 EXT BRIGHT ±025 ±000
7 EXT PICT. ±025 +002
8 EXT COLOR ±025 ±000
9 EXT TINT ±025 –016
10 EXT DETAIL 000 063 050
11 CMP BRIGHT ±025 –004
12 CMP PICT. ±025 –008
13 CMP COLOR 000 127 078
14 CMP TINT 000 127 072
15 CMP DETAIL 000 063 050
16 CMP R CUT ±025 –011
17 CMP G CUT ±025 ±000
18 CMP B CUT ±025 –001
19 CMP R DRV ±025 ±000
20 CMP B DRV ±025 ±000
21 WPL 000 / 001 001
22 B. B. SW 000 / 001 000
23 C TRAP 000 / 001 000
24 CORING 000 / 001 000
25 CMP CORING 000 / 001 001
26 TV SHARPF 000 / 001 001
27 EXT SHARPF 000 / 001 001
28 CMP SHARPF 000 / 001 001
29 RGB CONT 000 063 031
30 TV ID SEN S 000 / 001 000
31 EXT ID SEN 000 / 001 000
32 F ID 000 / 001 000
33 Y MUTE 000 / 001 000
34 AUDIO ATT 000 127 127
35 SUB CONT 000 015 008
16 No. 51786
AV-27F702
No. Setting (Adjustment) item Variable range Initial setting value
36 R Y GAIN 000 / 001 001
37 CMP R Y GA 000 / 001 001
38 G Y PHASE 000 / 001 000
39 CMP G Y PH 000 / 001 000
40 CD MATRIX 000 003 003
41 CMP CD MAT 000 003 002
42 BLACK ST 000 003 001
43 DC REST 000 003 001
44 COLOR GMM 000 / 001 000
45 UV/CBCR 000 / 001 001
46 AT FLESH 000 / 001 000
47 ABL GAIN 000 003 000
48 ABL ST PNT 000 003 003
49 RGB ABCL 000 / 001 001
50 TV BPF / TOF 000 / 001 000
51 EXT BPF / TOF 000 / 001 000
52 GMM PNT 000 003 003
53 SVM GAIN 000 003 002
54 CMP SVM GA 000 003 002
55 SVM PHASE 000 / 001 000
56 AUDIO SW 000 / 001 000
57 BUZZ 000 / 001 000
58 IF FREQ 000 / 001 000
59 RF AGC 000 063 045
60 AFT MUTE 000 / 001 000
61 AFT SENS 000 / 001 001
62 R/G DRV SW 000 / 001 001
63 BLK SW 000 / 001 000
64 V S COR 000 015 012
65 V LIN 000 015 008
66 V SIZE 000 127 065
67 V AGC 000 / 001 000
68 V CENTER 000 063 053
69 TV AFC 000 003 000
70 EXT AFC 000 003 002
71 V POSI 000 007 000
72 H POSI 000 031 011
73 H SIZE 000 063 023
74 TV V FREQ 000 003 000
75 EXT V FREQ 000 003 003
76 SIDE PIN 000 063 027
77 STAND BY 000 / 001 000
78 TRAPEZ 000 063 035
79 V RAMP REF 000 / 001 001
80 V 48HZ 000 / 001 000
81 V EHT 000 007 000
82 TOP PIN 000 031 010
No. 51786 17
AV-27F702
No. Setting (Adjustment) item Variable range Initial setting value
83 H EHT 000 007 000
84 BTM PIN 000 031 012
85 V BLK LOW 000 003 000
86 V BLK UP 000 003 000
87 CAPTION IN 000 / 001 000
88 H BLK 000 / 001 000
89 SCREEN 000 / 001 000
90 ACB SW 000 / 001 000
91 ACB PULSE 000 015 007
92 OVER MODU 000 / 001 001
93 CB/CR FIL 000 / 001 001
94 TEST 000 255 128
95 RF S/N TY 000 002 002
96 EXT S/N TY 000 002 002
97 RF SN YC E 000 255 005
98 RF SN YC F 000 255 016
99 RF SN YC G 000 063 032
100 RF SN YC H 000 255 025
101 EX SN YC E 000 255 005
102 EX SN YC F 000 255 016
103 EX SN YC G 000 063 032
104 EX SN YC H 000 255 025
105 RF SN VC 1 000 063 000
106 RF SN VC 2 000 063 007
107 RF SN VC 3 000 063 014
108 RF SN VC 4 000 063 021
109 EX SN VC 1 000 063 000
110 EX SN VC 2 000 063 007
111 EX SN VC 3 000 063 014
112 EX SN VC 4 000 063 021
113 COR LEVEL 000 003 003
114 VNR CHK 000 255 003
115 YC SN TIME 000 255 005
116 VC SN TIME 000 255 005
117 VM DATA A ±127 +008
118 VM DATA B ±127 –004
119 VM DATA C ±127 –016
120 VM DATA D 000 / 001 001
121 VC SN STOP 000 255 010
18 No. 51786
SOUND MODE
No. Setting (Adjustment) item Variable range Initial setting value
1 NOISE DET. 000 / 001 001
2 IN LEVEL 000 063 025
3 FH MONITOR 000 / 001 000
4 STEREO VCO 000 063 030
5 PILOT CAN. 000 / 001 000
6 FILTER 000 063 030
7 LOW SEP. 000 063 028
8 HI SEP. 000 063 025
9 5FH MON. 000 / 001 000
10 SAP VCO 000 063 003
11 IN GAIN 000 / 001 000
12 FIL. OFFSET 000 010 000
13 BBE BASS ±015 +001
14 BBE TRE ±015 –001
THEATER MODE
Setting (Adjustment) item Variable range Initial setting value
AV-27F702
TINT ±20 –06
COLOR ±20 –03
PICTURE ±50 –15
BRIGHT ±20 ±00
DETAIL ±20 +03
R CUT. ±20 ±00
G CUT. ±20 ±00
B CUT. ±20 ±00
R DRIVE ±99 +07
B DRIVE ±99 –25
DC REST. 00 03 01
BLK ST. 00 03 00
GMM PNT 00 03 01
CD MATRIX 00 03 01
RY GAIN 00 / 01 01
GY PHASE 00 / 01 00
CORING 00 / 01 01
CMP CD M 00 03 01
CMP RY G 00 / 01 01
CMP GY P 00 / 01 00
CMP COR 00 / 01 01
OTHERS MODE
No. Setting (Adjustment) item Variable range Initial setting value
1 OSD POS. 000 007 002
2 CCD POS. 000 015 003
3 EOSEL 000 / 001 000
4 MENU COLOR 000 — –030 –010
5 MENU PICT. 000 — –030 –010
6 MENU BRI. 000 — –030 –010
No. 51786 19
AV-27F702
LOW LIGHT MODE
Setting (Adjustment) item Variable range Initial setting value
R CUTOFF 0 255 85
G CUTOFF 0 255 85
B CUTOFF 0 255 85
HIGH LIGHT MODE
Setting (Adjustment) item Variable range Initial setting value
R DRIVE 0 127 60
B DRIVE 0 127 60
RF AFC MODE
Setting (Adjustment) item Variable range Initial setting value
RF AFC ON / OFF ON
FINE -77 +77 ± × ×
I2C BUS CTRL MODE
Setting (Adjustment) item Variable range Initial setting value
I2C BUS ON/OFF [FIXED ON]
DO NOT ADJUST
DO NOT ADJUST
20 No. 51786
ADJUSTMENTS
B1 POWER SUPPLY
Item
Measuring
instrument
AV-27F702
Test point Adjustment part Description
Check of B1 POWER SUPPLY
DC Voltmeter R507 C504
ADJUSTMENT OF RF AGC
Item
RF AGC adjustment
Measuring
instrument
1. Receive a black-and-white signal.
side (B1)
Q511 heatsink ( )
Test point Adjustment part Description
No.59 RF AGC
2. Connect the DC Voltmeter to R507 C504 side (B1) and Q511 heatsink ( ).
3. Confirm that the voltage is DC134V .
1. Receive a broadcast.
2. Select the No.59 RF AGC of the PICTURE MODE.
3. Press the MUTE key of the remote control unit and turn off color.
4. With the LEFT key of the remote control unit, get noise in the screen picture. (0 side of setting value)
5. Press the RIGHT key of the remote control unit and stop when noise disappears from the screen.
6. Change to other channels and make sure that there Is no irregular­ity.
7. Press the MUTE key and get color out.
+2V
-2V
ADJUSTMENT OF FOCUS
Item
FOCUS adjustment
Measuring
instrument
Signal generator
Test point Adjustment part Description
FOCUS VR [In HVT]
H VR [In HVT]
Notes:
Proceed to the following this adjustment after having completed the
adjustments of B1 POWER SUPPLY, SUB BRIGHT and PICTURE.
Set VIDEO STATUS to “STANDARD.
1. Receive a crosshatch signal.
2. While looking at the screen center, adjust the FOCUS VR so that the horizontal lines will be clear and in fine detail.
3. Adjust the H VR so that the vertical lines will be clear and in fine detail.
4. Make sure that the picture is in focus even when the screen gets darkened.
Note:
The final adjustment of convergence must be done after the FOCUS adjustment. (Convergence is changed by FOCUS adjustment.)
No. 51786 21
AV-27F702
ADJUSTMENT OF WHITE BALANCE
Item
Measuring
instrument
Test point Adjustment part
Description
WHITE BALANCE (Low Light) Adjustment
Signal generator
[LOW LIGHT] MODE
BRIGHT
999
R CUTOFF
REMOTE CONTROL UNIT
H.LINE ON
999 999 999
G CUTOFF
H.LINE OFF EXIT
123
R CUTOFF G CUTOFF B CUTOFF
456
R CUTOFF G CUTOFF B CUTOFF
789
No.1 BRIGHT
R CUTOFF G CUTOFF B CUTOFF
SCREEN VR [In HVT]
BRIGHT B CUTOFF
Note :
Set VIDEO STATUS to “STANDARD.
1. Receive a black-and-white signal.(Color off)
2. Select the [LOW LIGHT] MODE from the SERVICE MENU.
3. Set the initial setting value of BRIGHT is 063 with the LEFT / RIGHT key of the remote control unit.
4. Set the initial setting value of R CUTOFF, G CUTOFF and B CUT­OFF is 085 with the 4 to 9 key of the remote control unit.
5. Display a single horizontal line by pressing the 1 key of the remote control unit.
6. Turn the screen VR all the way to the left.
7. Turn the screen VR gradually to the right from the left until either one of the red, blue or green colors appears faintly.
8. Adjust the two colors which did not appear until the single horizontal line that is displayed becomes white using the 4 to 9 keys of the remote control unit.
9. Turn the screen VR to where the single horizontal line glows faintly.
10.Press the 2 key to return to the regular screen.
9 The 3 EXIT key is the cancel key for the WHITE BALANCE.
WHITE BALANCE (High Light) Adjustment
Signal generator
[HIGH LIGHT] MODE
999
R DRIVE
H.LINE ON
HIGHT LIGHT
REMOTE CONTROL UNIT
H.LINE OFF EXIT
999
123
R DRIVE B DRIVE
456
R DRIVE B DRIVE
789
R DRIVE B DRIVE
B DRIVE
Notes:
Proceed to the following this adjustment after having completed the
adjustment of LOW LIGHT WHITE BALANCE.
Set VIDEO STATUS to STANDARD.
1. Receive a black-and-white signal. (Color off)
2. Select the [HIGH LIGHT] MODE from the SERVICE MENU.
3. Set the initial setting value of R DRIVE and B DRIVE is 060 with the 4 , 6 , 7 and 9 keys of the remote control unit.
4. Adjust the screen until it becomes white using the 4 , 6 , 7 and 9 keys of the remote control unit.
9 The 3 (EXIT) key is the cancel key for the WHITE BALANCE.
22 No. 51786
ADJUSTMENT OF BRIGHT
Item
Measuring
instrument
AV-27F702
Test point Adjustment part Description
SUB BRIGHT Adjustment
ADJUSTMENT OF CONTRAST
Item
SUB CONTRAST Adjustment
Measuring
instrument
Test point Adjustment part Description
No.1 BRIGHT Notes:
Proceed to the following this adjustment after having completed the adjustments of LOW LIGHT WHITE BALANCE and HIGH LIGHT WHITE BALANCE.
Set VIDEO STATUS to “STANDARD.
1. Receive a broadcast.
2. Select the No.1 BRIGHT of the PICTURE MODE.
3. Set the initial setting value of the No.1 BRIGHT with the LEFT /
RIGHT key of the remote control unit.
4. If the brightness is not best with the initial setting value, make fine
adjustment of the No.1 BRIGHT until you get the optimum bright­ness.
No.2 PICTURE
Notes:
Proceed to the following this adjustment after having completed the adjustment of SUB BRIGHT.
Set VIDEO STATUS to “STANDARD.
ADJUSTMENT OF DEFLECTION
Item
V CENTER and TRAPEZIUM Adjustment
Measuring
instrument
Signal generator
Test point Adjustment part Description
No.68 V CENTER No.78 TRAPEZ
1. Receive a broadcast.
2. Select the No.2 PICTURE of the PICTURE MODE.
3. Set the initial setting value of the No.2 PICTURE with the LEFT /
RIGHT key of the remote control unit.
4. If the contrast is not best with the initial setting value, make fine
adjustment of the No.2 PICTURE until you get the optimum con­trast.
Note:
Proceed to the following this adjustment after having completed the adjustments of SUB BRIGHT and SUB CONTRAST.
1. Receive a crosshatch signal.
2. Adjust the No.68 V CENTER of the PICTURE MODE to be the same
between the CRT vertical center and crosshatch vertical center.
3. Adjust the No.78 TRAPEZ of the PICTUER MODE to be the vertical
lines straight.
4. Confirm the vertical lines to be straight. If it is not straight, adjust to
be straight at the No.78 TRAPEZ.
No. 51786 23
AV-27F702
Item
V-SIZE and V-LINEARITY Adjustment
Screen size 92%
H SIZE and H POSITION Adjustment
Screen size
Measuring
instrument
Signal generator
Signal generator
Test point Adjustment part Description
Screen size
Picture size 100%
Screen size 90%
No.66 V SIZE No.65 V LIN
Picture size 100%
No.73 H SIZE No.72 H POSI
Picture size 100%
Note:
Proceed to the following this adjustment after having completed the adjustments of SUB BRIGHT and SUB CONTRAST.
1. Receive a crosshatch signal.
2. Select the No.66 V SIZE of the PICTURE MODE to squeeze the laster.
3. Adjust the No.65 V LIN of the PICTURE MODE to be symmetrical.
4. Adjust the No.66 V SIZE until the vertical screen size is 92%.
Note:
Proceed to the following this adjustment after having completed the adjustments of FOCUS, SUB BRIGHT, SUB CONTRAST, V CENTER, TRAPEZIUM, V-SIZE and V-LINEARITY.
1. Receive a crosshatch signal.
2. Select the No.73 H SIZE of the PICTURE MODE.
3. Set the initial setting value of the No.73 H SIZE with the LEFT / RIGHT key of the remote control unit.
4. Adjust the No.73 H SIZE until the horizontal screen size is 90%.
5. Adjust the No.72 H POSI until the screen will be horizontally centered.
Picture size 100%
SIDE PIN and CORNER PIN Adjsutment
Signal generator
Straight Straight
No.76 SIDE PIN No.82 TOP PIN No.84 BTM PIN
Note:
Proceed to the following this adjustment after having completed the adjustments of FOCUS, SUB BRIGHT, SUB CONTRAST, V CENTER, TRAPEZIUM, V-SIZE and V-LINEARITY.
1. Receive a crosshatch signal.
2. Adjust such that vertical 2nd lines from left and right to be straight at
3. Adjust the end of vertical 2nd lines from left and right to be straight
24 No. 51786
the No.76 SIDE PIN of the PICTURE MODE.
at the No.82 TOP PIN and the No.84 BTM PIN of the PICTURE MODE.
ADJUSTMENT OF CHROMA
Item
Measuring
instrument
AV-27F702
Test point Adjustment part Description
SUB COLOR adjustment
Signal generator Oscilloscope Remote control unit
Y
Cy
W
TP-B TP-E1( [CRT SOCKET PWB]
G
R
Mg
No.3 COLOR
)
Notes:
Proceed to the following this adjustment after having completed the adjustment of CONTRAST.
Set VIDEO STATUS to “STANDARD.
[ Method of adjustment without measuring instrument ]
1. Receive a broadcast.
2. Select the No.3 COLOR of the PICTURE MODE.
3. Set the initial setting value of the No.3 COLOR with the LEFT/RIGHT
key of the remote control unit.
4. If the color is not the best with the Initial setting value, make fine
adjustment of the No.3 COLOR until you get the optimum color.
(A)
(–) 0V
B
(+)
Notes:
Proceed to the following this adjustment after having completed the adjustment of CONTRAST.
Set VIDEO STATUS to “STANDARD.
[ Method of adjustment using measuring instrument ]
1. Input the full field color bar signal (75% white).
2. Select the No.3 COLOR of the PICTURE MODE.
3. Set the initial setting value of the No.3. COLOR with the LEFT/RIGHT
key of the remote control unit.
4. Connect the oscilloscope between TP-B and TP-E1.
5. Adjust COLOR and bring the value of (A) in the illustration to the
voltage +6V (V
W-B).
SUB TINT adjustment
Signal generator Oscilloscope Remote control unit
Y
Cy
W
TP-B TP-E1( ) [CRT SOCKET PWB]
G
R
Mg
No.4 TINT
Notes:
Proceed to the following this adjustment after having completed the adjustment of CONTRAST.
Set VIDEO STATUS to “STANDARD.
[ Method of adjustment without measuring instrument ]
1. Receive a broadcast.
2. Select the No.4 TINT of the PICTURE MODE.
3. Set the initial setting value of the No.4 TINT with the LEFT/RIGHT
key of the remote control unit.
4. If the tint is not the best with the initial setting value, make fine ad-
justment of the No.4 TINT until you get the optimum tint.
(–) 0V (+)
B
(B)
Notes:
Proceed to the following this adjustment after having completed the adjustment of CONTRAST.
Set VIDEO STATUS to “STANDARD.
[ Method of adjustment using measuring instrument ]
1. Input the full field color bar signal (75% white).
2. Select the No.4 TINT of the PICTURE MODE.
3. Set the initial setting value of the No.4 TINT with the LEFT/RIGHT
key to the remote control unit.
4. Connect the oscilloscope between TP-B and TP-E1.
5. Adjust TINT and bring the value of (B) in the illustration to the volt-
age +2V (VW-Mg).
No. 51786 25
AV-27F702
ADJUSTMENT OF MTS CIRCUIT
Item
Measuring
instrument
Test point Adjustment part Description
MTS INPUT LEVEL check
MTS STEREO VCO adjustment
MTS SAP VCO adjustment
Signal generator
Frequency counter
Signal generator
Frequency counter
[MPX] Connector 2
pin AUDIO R
3 pin GND
[MPX] Connector 4 pin TP_952.5 3 pin GND 2 pin AUDIO_R
No.2 IN LEVEL
No.3 FH MONITOR
No.4 STEREO VCO
No.9 5FH MON.
No.10 SAP VCO
1. Select the No.2 IN LEVEL of the SOUND MODE.
2. Verify that the No.2 IN LEVEL is set at its initial setting value.
Note: Menu MTS is set to STEREO
1. Receive a RF signal (nonmodulated sound signal) from the antenna terminal.
2. Select the No.3 FH MONITOR of SOUND MODE, and change the setting value from 0 to 1.
3. Connect the Frequency Counter to pin 2 of [MPX] connector and GND (Pin 3 of [MPX] connector).
4. Select the No.4 STEREO VCO.
5. Set the initial setting value of the No.4 STEREO VCO with the LEFT/ RIGHT key of the remote control unit.
6. Adjust the No.4 STEREO VCO so that the frequency counter will display 15.73kHz±0.1kHz.
7. Select the No.3 FH MONITOR of the SOUND MODE, and reset the setting value from 1 to 0.
1. Receive a RF signal (non modulated sound signal) from the an­tenna terminal.
2. Connect between pin 4 of [MPX] connector and GND (Pin 3 of [MPX] connector) through 1MØ Resistor.
3. Select the No.9 5FH MON. of the SOUND MODE, and reset the setting value from 0 to 1.
4. Connect the Frequency Counter to pin 2 of [MPX] connector and GND (Pin 3 of [MPX] connector) .
5. Select the No.10 SAP VCO.
6. Set the initial setting value of the No.10 SAP VCO with the LEFT/ RIGHT key of the remote control unit.
7. Adjust the No.10 SAP VCO so that the frequency counter will dis­play 78.67kHz±0.5kHz.
8. Select the No.9 5FH MON. of the SOUND MODE, and reset the setting value from 1 to 0.
MTS FILTER check
MTS SEPARATION adjustment
L-Channel signal waveform
1 cycle
TV audio multiplex signal generator
Oscilloscope
[MPX] Connector 1 pin AUDIO_L 2 pin AUDIO_R 3 pin GND
R-Channel crosstalk portion
Minimum
No.6 FILTER
No.7 LOW SEP.
No.8 HI SEP.
1. Select the No.6 FILTER of the SOUND MODE.
2. Verify that the No.6 FILTER is set at its initial setting value.
Note: Menu MTS is set to STEREO
1. Input a stereo L signal (300Hz) from the TV audio multiplex signal
2. Connect an oscilloscope to pin 1 of [MPX] connector, and display
3. Change the connection of the oscilloscope to pin 2 of [MPX] con-
4. Select the No.7 LOW SEP. of the SOUND MODE.
5. Set the initial setting value of the No.7 LOW SEP. with the LEFT/
6. Adjust the No.7 LOW SEP. so that the 300Hz signal level will be-
7. Change the signal to 3kHz, and connect an oscilloscope to pin 1 of
8. Adjust the No.8 HI SEP. so that the 3kHz signal level will become
26 No. 51786
generator to the antenna terminal.
one cycle portion of the 300Hz signal.
nector, and enlarge the voltage axis.
RIGHT key of the remote control unit.
come minimum.
[MPX] connector.
minimum.
HOW TO CHECK THE HIGH VOLTAGE HOLD DOWN CIRCUIT
1. HIGH VOLTAGE HOLD DOWN CIRCUIT
After repairing the high voltage hold down circuit shown in Fig. 1. This circuit shall be checked to operate correctly.
2. CHECKING OF THE HIGH VOLTAGE HOLD DOWN CIRCUIT
(1) Turn the POWER SW ON.
S1
(2) As shown in Fig. 1, set the resistor (between (3) Make sure that the screen picture disappears. (4) Temporarily unplug the power cord. (5) Remove the resistor (between S1 connector 2 & 3 ). (6) Again plug the power cord, make sure that the normal picture is displayed on the screen.
RY951
connector 2 & 3 ).
RESISTOR
20.3 k ± 101 1/4 W
AV-27F702
POWER
ON OFF
R952
R532
D535
R951
R533
Q531
Q951
Q532
R534
+
C533
D534
D532 BW
D531
Fig. 1
23
R537 FR525
R535R538
S1 CONNECTOR
+
HEATER
T502
4
D525
C525
No. 51786 27
AV-27F702
SELF CHECK FUNCTIONS
1. Outline
This model has self check functions given below. When a malfunction has been detected, the POWER is turned off and the LED flashes to inform of the failure . The malfunction is detected by the signal input state of the control line connected to the microcomputer.
2. Self check items
Check item Details of detection Method of detection State of malfunction
Over-current protector
3. Self check indicating function
The self-check function begins detection about 5 seconds after power is supplied. In the event a malfunction is detected, the power is cut off immedi­ately. At this time, the ON-TIMER LED flashes to inform of the malfunc­tion.
[ON-TIMER LED indication]
The ON-TIMER LED flashes at 0.5 seconds intervals.
Operation of B1 protector circuit. The microcomputer detects at 1
second intervals. If NG is detected for more than 200 ms, a malfunction is inter­preted.
POWER Supplied
After about 5 seconds
Start of detection
When a malfunction has been detected, the POWER is turned off. While the POWER is being turned off , the power key of the remote controller is not opera­tional until the power code is taken out and put in again.
Malfunction is detected
POWER OFF
Flashing ON-TIMER LED
28 No. 51786
JVC SERVICE & ENGINEERING COMPANY OF AMERICA
DIVISION OF JVC AMERICAS CORP.
Head office : East Coast : Midwest : West Coast : 5665 Corporate Avenue, Cypress, California 90630 (714)229-8011 Southwest : 10700 Hammerly, Suite 105, Houston, Texas 77043 (713)935-9331 Hawaii : 2969 Mapunapuna Place, Honolulu, Hawaii 96819 (808)833-5828 Southeast : 1500 Lakes Parkway, Lawrenceville, Georgia 30243 (770)339-2582
1700 Valley Road, Wayne, New Jersey 07470 (973)315-5000 10 New Maple Avenue, Pine Brook, New Jersey 07058 (973)396-1000 705 Enterprise St. Aurora, Illinois 60504
(630)851-7855
JVC CANADA INC.
Head office : 21 Finchdene Square Scarborough, Ontario M1X 1A7 (416)293-1311 Vancouver : 13040 Worster Court Richmond B.C. V6V 2B3 (604)270-1311
27F702S-UCM #4
Printed in Japan VP0101 SW
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