JVC DT-V2000SU Service Manual page 77

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DT-V2000SU
HOW TO CHECK THE HOLD DOWN CIRCUIT
1. HIGH VOLTAGE HOLD DOWN CIRCUIT
After repairing the high voltage hold down circuit shown in Fig.1.
This circuit shall be checked to operate correctly.
2. CHECKING OF THE HIGH VOLTAGE HOLD DOWN CIRCUIT
Adjustment parts FUNCTION
VR701 X-RAY DETVR FX-2056A
R551 HIGH VOLTAGE ADJUSTMENT VR FX-2107A
(1) Connect the high voltage meter to anode.
(2) Input the NTSC cross-hatch signal to input B terminal.
PW Board ASS'Y
[MAIN PWB ASS'Y]
[SUB DEF PWB ASS'Y]
(3) Then turn the R551 gradually, so that the high voltage become 30.0kV±0.2kV.
(4) Slowly turn the VR701 gradually, so that the X-RAY protector turn on.
(If turn on the X-RAY protector, screen display deleted and indication of the input B LED (on the front panel) has flashed.)
(5) Turn off the power.
(6) Lock the VR701 by applying the bond .
(7) Make sure that the voltage is 30kV±0.5kV. If illegal, adjust again in step (3) to step (7).
(8) Then adjust the high voltage adjustment surely shown in page before.
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C555I
R550
IC505
B1
DEF PRO
MODULE
R552
Q518
T
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IC551
HV ERROR AMP
SUB DEF PWB
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VR701
Q510
D512
C530
D511
MIAN PWB
T502 HVT
D509
D510
B1
D513
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