JVC AV-21VT14/P Service Manual page 10

3.2 REPLACEMENT OF MEMORY IC
3.2.1 MEMORY IC
This TV uses the following memory IC.
Memory IC: IC702 on MAIN PWB
The memory IC memorizes data for correctly operating the video
and deflection circuits. When replacing the memory IC, be sure
to use the same type IC written with the initial values of data. In
other words, use the specific IC listed in "PRINTED WIRING
BOARD PARTS LIST". For its mounting location, refer to
"ADJUSTMENT LOCATIONS".
3.2.2 PROCEDURE FOR REPLACING MEMORY IC
1. Power off
Switch the power off and unplug the power cord from the wall
outlet.
2. Replacing the memory IC
Replace the memory IC with new one. Be sure to use the
memory IC written with the initial data values.
3. Power on
Plug the power cord into the wall outlet and switch the power on.
4. Check and setting of SYSTEM CONSTANT SET:
(1) Press the [DISPLAY] key and the [PICTURE MODE] key
on the remote control unit simultaneously.
The SERVICE MENU screen will be displayed.(See
Fig.1.)
(2) In the SERVICE MENU, press the [DISPLAY] key and
[PICTURE MODE] key simultaneously. Then, the
SYSTEM CONSTANT
displayed.(See Fig.2.)
(3) Check whether the setting values of the SYSTEM
CONSTANT SET are the same as those indicated in
Table 1.
If the value is different, select the setting item with the
MENU [ ] / [ ] key, and set the correct value with the
MENU [ ] / [ ] key.
(4) Press the [DISPLAY] key twice to return to the normal
screen.
5. Receive channel setting
Refer to the OPERATING INSTRUCTIONS and set the
receive channels (channels preset).
6. User setting
Check the user setting values in Table 2 and Table 3. If setting
value is different, set the correct value.
For setting, refer to the OPERATING INSTRUCTIONS.
7. Setting of SERVICE MENU
Verify the setting for each setting item in the SERVICE
MENU.(See Table 4.) If readjustment is necessary, perform
adjustment referring to "ADJUSTMENTS PROCEDURE".
NAME OF REMOTE CONTROL KEYS
DISPLAY / BACK
MENU
PICTURE
MODE
1-10 (No.YA140)
SET screen will be
MENU
MENU
MENU
SERVICE MENU
SERVICE MENU
1. IF 2. V/C
3. AUDIO
4. DEF
5. VSM W/B 6. S TATUS
7. PLUG & PLAY (ON)
1-7 : SELECT DISPLAY : EXIT
******* **** ***** *****
**** **** *** ***
Fig.1
SYSTEM CONSTANT-1
SYSTEM CONSTANT SET 1
SYSTEM OTHERS
COMB NO
TILT NO
SUPER BASS NO
: SEL : OPE DISP : EXIT
SYSTEM CONSTANT-2
SYSTEM CONSTANT SET 2
SOUND STEREO
BLUE BACK MUTE NO
ECO SENSOR YES
: SEL : OPE DISP : EXIT
SYSTEM CONSTANT-3
SYSTEM CONSTANT SET 3
SURROUND YES
PICTURE BOOSTER NO
COMPONENT YES
S INPUT YES
: SEL : OPE DISP : EXIT
Fig.2