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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 (
Note:
A/V Inputs only
available
on
some models
IC 551
C552
A11
T
U
N
E
R
TP16
FA1
CLK
DATA TP15
MOMENTARILY CONNECT A JUMPER FOR ENTERING SERVICE MODE (FA1 to FA2 )
131.0V 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 hot
ground ( ).
3. Confirm that B+ voltage is 131.0V ± 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 the correct
ground for the (-) lead of the DVM.
C809(+)
TPD9
C552(+)
TPD8
CATHODE OF D554
Adjust Picture Menu for normalized video adjustments.
Q002
IC 002
IC 001
1
64
32
33
IC 552
D002
IC 101
1
52
26
27
SP
FA2
Figure 5. A-Board Main Components and Test Points
+131V ± 2.5V
+13.0V ± 2V
+20.0V ± 2V (27&25")
+8.0V ± 1V (32")
+27.4V ± 2V
+220.0V ± 15V (27"&32")
+220.0V ± 5V (25")
) — Tuner shield, IC451's heat sink or FA2 (Fig. 5,Fig. 6).
A-BOARD TEST LOCATIONS
COLD (
)
HOT (
)
RL801
IC 803
F801
C551
C552
TPD8
B+ 5V Source Voltages
Volatile 5V:
C572, + side = IC552 pin 3, Tuner BPL, IC101 (IF 5V).
MPU 5V:
Emitter Q002 = IC001 (V
Standby 5V:
IC001 (key in 1), I
Receiver.
B+ 9V Source Voltage
IC551 pin 3 = IC101 (IF 9V), Tuner (BM).
B+ 12V (Stand- by)
Cathode D002= RL801 (on-off relay).
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 29.25kV ± 1.25kV.
- 11 -
IC 451
C809
TPD9
D554
FOCUS
SCREEN
, AV
).
DD
DD
2
C EEPROM (IC002), Remote
Note: +16V when power is on
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