1-20 (No.YA073)
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
Signal
generator
DC voltmeter
R927 : TP-91
HEAT SINK
(IC421) : TP-E
[MAIN PWB]
(1) Receive the black and white signal. (color off)
(2) Connect the DC voltmeter to the TP-E and TP-91
(R927).
(3) Confirm that the voltage is DC134V±2V.
HIGH VOLTAGE
HOLD DOWN
check
Resistor
(18.0kΩ,1/4W)
X connector
1-pin
3-pin
[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 X
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.
T521
RESISTOR
HEATER
X CONNECTOR3 2 1
18.0 k 1%
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 any broadcast.
(2) Select 9.VCO from the SERVICE MODE.
(3) Change 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 crosshatch signal.
(2) While looking at the screen, adjust the FOCUS VR
to the vertical and horizontal lines will be clear and in
fine detail.
(3) Make sure that the picture is in focus even when the
screen gets darkened.
To Next Page
Loading...
Need help?
General
