Replacement Of Memory Ic - JVC AV-21PM Service Manual

AV-21PM

REPLACEMENT OF MEMORY IC

1. MEMORY IC
This TV uses the following memory IC.
Memory IC: IC1702 on MAIN PW Board
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, re-
fer to "ADJUSTMENT LOCATIONS".
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 SYS-
TEM CONSTANT SET screen will be displayed. (See
Fig. 2.)
3) Check whether the setting values of the SYSTEM CON-
STANT SET are the same as those indicated in Table
1. If the value is different, select the setting item with
the MENU a 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).
NAME OF REMOTE CONTROL KEYS
ECO
SENSOR
SYSTEM
COLOUR
TV/VIDEO
I / II
OFF
TIMER
CHANNEL
SCAN
DISPLAY
DISPLAY
−
MENU –
CHANNEL
6
POWER
PICTURE
SOUND
MODE
PICTURE
MODE
1 2 3
4 5 6
7 8 9
RETURN+ -/- -
0
MENU
MUTING
MENU +
+
MENU
MENU
+
−
VOLUME
(6) User setting
Check the user setting values in Table 2, and 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 3.) If readjustment is necessary, per-
form adjustment referring to "SERVICE ADJUSTMENTS".
SYSTEM CONSTANT - I
COLOUR
BILINGUAL
TUNER
ECO SENSOR
LANGUAGE
a: SELECT
− / + : OPERATE
SYSTEM CONSTANT - II
B/B SOUND
LOCK
COLOUR AUTO
QSS
ALC
TEXT RATE
a: SELECT
− / + : OPERATE
SYSTEM CONSTANT - III
AMP TUNER
VNR
EW-PIN IC
a: SELECT
− / + : OPERATE
No. 56055
SERVICE MENU
SERVICE MENU
1. IF 2. V/C
3. DEF 4. VSM PRESET
5. PRESET
6. TURBO TIMER OFF
1-6 : SELECT DISP : EXIT
.
.
Fig. 1
SYSTEM CONSTANT SET 1/3
: MULTI
: NO
: MU
: YES
: E / R / A / F
DISP : EXIT
SYSTEM CONSTANT SET 2/3
: OFF
: 180
: NO
: MINT
: NO
: 20
DISP : EXIT
SYSTEM CONSTANT SET 3/3
: NO
: YES
: YES
DISP : EXIT
Fig. 2