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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 IC801’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 TO ENTER SERVICE MODE (FA1 to FA2)
130.0V B+ Voltage Confirmation
1.
Set the Bright and the Contrast to Minimum by
using the Picture Menu.
2.
Connect the DVM between C825 (+ side) or
TPD14 and cold ground (
).
3.
Confirm that B+ voltage is 130.0V ± 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 Contrast 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.
Figure 4. A-Board Main
Components and Test Points
(Components within dotted
areas are located on
trace side)
LOCATION
VOLTAGE
TPD8
26.0V ± 2.0V
TPD9
13.0V ± 2.0V
IC551 Pin3
9.0V ± 0.25V
IC552 Pin3
5.0V ± 0.25V
D554 Cathode
220V ± 15V
Содержание CT27G6DE - 27" COLOR TV
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