-15-
Service Adjustments
Following adjustments are not required to readjust when replacing the memory IC.
Note: +B (+140V) Voltage Check and Grayscale Adjustment
must be completed before attempting High Voltage Check.
(1) Connect high voltage voltmeter negative lead to
ground, and connect + lead to anode of picture tube.
(2) Tune receiver to an active channel and confirm TV is
operating properly.
(3) Maximize the beam current by adjusting the contrast
and brightness controls to maximum. Confirm high
voltage is within 22.0 KV and 24.0 KV at maximum
beam current.
(4) Eliminate the beam current by adjusting the contrast
and brightness controls to minimum. Confirm high
voltage does not exceed 25.0 KV at zero beam current.
If reading is not within range, check horizontal circuit.
No high-voltage adjustment is provided on this chassis.
HIGH VOLTAGE CHECK
(1) Connect DC meter to TP-B and the ground.
(2) Tune the receiver to an active channel and synchro-
nized picture. Select NATURAL picture mode by press-
ing the PICTURE MODE button on the remote control.
(3) Adjust B-voltage to be 140 ± 0.5V DC by using VR631.
B-VOLTAGE SUPPLY CHECKING
(1) Receive the monochrome circular pattern.
(2) Set the brightness to normal and contrast to maximum.
(3) Adjust the focus control on the F.B.T. for the best focus
on the screen centre.
FOCUS ADJUSTMENT
MAIN BOARD
B-Voltage Supply Adjustment
MAIN BOARD
TP-B
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