JVC AV-N29F45/S Service Manual page 21

4.8 ADJUSTMENT PROCEDURE
4.8.1 CHECK ITEM
Measuring
Item
instrument
B1 POWER DC voltmeter S1 Connector
SUPPLY check
HIGH VOLTAGE Resistor
HOLD DOWN
check
RESISTOR
B1
5 4 3
4.8.2 TUNER / IF CIRCUIT
Measuring
Item
instrument
IF VCO Remote
control unit
TOO HIGH GOOD
SYNC:
AFC
FINE
4.8.3 FOCUS
Measuring
Item
instrument
FOCUS Signal
generator
Test point Adjustment part
1-pin : TP-E
5-pin : TP-91
[MAIN PWB]
S1 connector
1-pin : TP-E
3-pin : X-RAY1
[MAIN PWB]
2 1 S1 CONNECTOR
Test point Adjustment part
[9.VCO]
CW transf. (T111)
[MAIN PWB]
AFC STATUS
(Turn to green)
TOO LOW
YES
ON
0
Test point Adjustment part
FOCUS VR
[In HVT]
(1) Receive the black-and-white signal. (color off)
(2) Connect the DC voltmeter to the TP-E and TP-
91(B1) of S1 connector.
(3) Confirm that the voltage is DC134.5V±2V.
• After reparing the high voltage hold down circuit. This
circuit shall be checked to operate correctly.
(1) Turn the power switch to on.
(2) Refer to the figure, connect the resistor between S1
connector 1-pin and 3-pin.
(3) Make sure that the screen picture disappeares.
(4) Disconnect the power plug.
(5) Remove the resistor.
(6) Again connect the power plug.
(7) Turn the power switch to on.
HEATER
(8) Make sure that the normal picture is displayed on the
screen.
HVT
4
• It must not adjust without inputting the RF signal.
(1) Receive the broadcast.
(2) Select 9.VCO from the SERVICE MODE.
(3) Set the "AFC" to "OFF" and "FINE" to "0".
(4) Confirm that the color change from "TOO HIGH" to
"TOO LOW" by CW transf. on MAIN PWB, and
check the "SYNC" is "YES".
(5) Adjust CW transf. until "GOOD" letters turns green.
And then confirm that the "SYNC" is "YES" again.
Adjustment can be done in this statement.
(6) It return the "AFC" to "ON".
(7) Push the [EXIT] key to exit the 9.VCO.
(1) Receive the cross-hatch signal.
(2) While watching at the screen, adjust the FOCUS VR
to the vertical and horizontal lines will be thinnest
and sharpest center horizontal line.
(3) Make sure that the picture is in focus even when the
screen gets darkened.
Description
Description
Description
(No.YA058)1-21