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Chassis Service Adjustment Procedures
All service adjustments are factory preset and should not require adjustment unless controls and/or
associated components are replaced.
Note: Connect the (-) lead of the voltmeter to the appropriate ground. Use IC803’s heat sink when the HOT ground
symbol ( ) is used. Otherwise, use COLD ground (
) — Tuner shield, IC451’s heat sink or FA2.
MOMENTARILY CONNECT A JUMPER FOR ENTERING SERVICE MODE (FA1 to FA2 )
132.0V B+ Voltage Confirmation
1.
Set the Bright and the Picture to Minimum by
using the Picture Menu.
2.
Connect the DVM between C809(+ side) and cold
ground (
).
3.
Confirm that B+ voltage is 132.0V ± 2.5V. This
voltage supplies B+ to the Horizontal Output &
Flyback circuits.
Source Voltage Chart
120V AC line input. Set the Bright and the Picture to
Minimum by using the Picture Menu. Use cold ground
(
) for the (-) lead of the DVM.
Adjust Picture Menu for normalized video adjustments.
High Voltage Check
1.
Select an active TV channel and confirm that
horizontal is in sync.
2.
Adjust Brightness and Picture using Picture Icon
menu so video just disappears.
3.
Confirm B+ 131V is within limit.
4.
Using a high voltage meter confirm that the High
Voltage is 27.7kV ± 1.25kV.
T
U
N
E
R
TP
1
8
/
S
IC001
A-BOARD
IC2302
D5
5
4
IC551
IC451
Q551
C809
-
+
TPD9
TPD8
C552
-
+
C572
-
+
IC6501
IC101
IC803
Figure 4.
A-Board Main
Components and
Test Points
LOCATION
VOLTAGE
TPD8
24.0V ± 2V
TPD9
13.0V ± 2V
C552 (+) side
8.0V ± 1V
IC551 Pin3
9.0V ± 0.5V
D554 Cathode
200V ± 15V
C572 (+) side
5.0V ± 0.25V
