1-22 (No.YA057)
4.8
ADJUSTMENT PROCEDURE
4.8.1 CHECK ITEM
4.8.2 TUNER / IF CIRCUIT
4.8.3 FOCUS
Item
Measuring
instrument
Test point
Adjustment part
Description
B1 POWER
SUPPLY check
DC voltmeter S1 Connector
1-pin : TP-E
5-pin : TP-91
[MAIN PWB]
(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.
HIGH VOLTAGE
HOLD DOWN
check
Resistor
(19.0k
Ω
,
1/4W)
S1 connector
1-pin : TP-E
3-pin : X-RAY1
[MAIN PWB]
• 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.
(8) Make sure that the normal picture is displayed on the
screen.
HVT
HEATER
4
CONNECTOR
S1
3
2
1
B1
4
5
Item
Measuring
instrument
Test point
Adjustment part
Description
IF VCO
Remote
control unit
[9.VCO]
CW transf. (T111)
[MAIN PWB]
• 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.
TOO HIGH GOOD TOO LOW
SYNC: YES
AFC ON
FINE 0
AFC STATUS
(Turn to green)
Item
Measuring
instrument
Test point
Adjustment part
Description
FOCUS
Signal
generator
FOCUS VR
[In HVT]
(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.
