JVC AV-21F1P Service Manual page 16

AV-21F1P
ADJUSTMENTS
B1 POWER SUPPLY CHECK
Measuring
Item
instrument
Check of Signal
B1 POWER Generator
SUPPLY DC
voltmeter
IF VCO ADJUSTMENT
Measuring
Item
instrument
Adjustment Signal
VCO (CW) Generator
Remote
control unit
SUB MENU: VCO (CW)
TOO HIGH
ABOVE REFERENCE
BELOW REFERENCE
TOO LOW
SYNC
RF AGC ADJUSTMENT
Measuring
Item
instrument
Adjustment Remote
of RF AGC control unit
FOCUS ADJUSTMENT
Measuring
Item
instrument
Adjustment Signal
of FOCUS generator
16
Test point Adjustment part
B1 (TP-91)
TP-E (" " " " " )
[B1
connector]
Test point Adjustment part
CW TRANSF.
(T111)
[MAIN PWB]
YELLOW
: YES
EXIT BY
EXIT
IT
Test point Adjustment part
60. RF AGC
Test point Adjustment part
FOCUS VR
[In HVT]
1. Receive a black and white signal (color off). (NTSC)
2. Connect a DC voltmeter between B1 (TP-91) and TP-E (")
(between pins 1 and 3 of the connector B1).
3. Make sure that the voltage is DC134.5
Under normal conditions, no adjustment is required.
1. Receive any broadcast. (Use a channel without offset fre-
quency.)
2. Select the sub menu screen VCO (CW) from the SERVICE
MENU. (More specifically, in the SERVICE MENU, press the
MENU 1/4 key to select VCO (CW) and then press the MENU
2/3 key to enter the sub menu screen VCO (CW) .)
3. Confirm that the color of "TOO HIGH" and "TOO LOW" changes
in yellow as you turn the CW TRANSF. At this time, check that
"SYNC: YES" appears on the screen.
4. Slowly turn the CW TRANSF. until "BELOW REFERENCE"
changes to yellow. Also, at this time, check that "SYNC: YES"
appears on the screen.
5. Press the EXIT key to return to the normal screen.
1. Receive any broadcast.
2. Select the sub menu screen PICTURE from the SERVICE
MENU.
3. Select 60. RF AGC with the MENU 1/4 key.
4. Press the MUTING key to turn off the color.
5. Press the MENU 2 key to get noise on the screen picture. (The
setting value will be decreased.)
6. Press the MENU 3 key until noise disappears from the screen.
7. Change to other channels and make sure that there is no ir-
regularity on the screen picture.
8. Press the MUTING key to turn on the color.
1. Receive a cross-hatch signal.
2. While watching the screen, adjust the FOCUS VR to make the
vertical and horizontal lines as fine and sharp as possible.
3. Make sure that, when the screen is darkened, the lines remain
in good focus.
No. 56033
Description
±
2.0V.
Description
Description
Description