Hitachi 57F59A Service Manual page 84

2.23 TROUBLE SHOOTING
2.23-01 TROUBLE SHOOTING for POWER CIRCUIT
No raster and no power (How to check LED's Diagnosis)
No
Raster
BACK TO ADJUSTMENTS
(Pow Def PWB)
Is Voltage
at D949(K) 5V? NO
YES
Is click sound
NO
of Relay heard?
YES
Is +B Voltage
at D945(K) is YES
about 115V?
NO
1.Turn OFF
Has Fuse F903
2.Wait for 3 seconds.
NO
blown? 3.Turn ON again after
YES
Check
I902.T902
I906.etc
Is Voltage
at pin(6) of PDS2 NO
3V or more?
YES
Check
E947, Q777,
QH01, Q701
I907 .I908
the power SW.
Is Green LED
turned OFF after
several seconds?
several seconds,and
observe green LED
carefully.
Check
Q980, Q981,
Appear with (8) and (11)
NO
etc.
Of PDT2 shorted?
Check
PDT2 pin(6)
-H out,
Is base Voltage
PDT2 pin(10)
NO
Of Q709 normal?
SW+10.5V
etc.
Check
T702, R748,
At both ends of T702
NO
R730
(primary side)
etc.
Check
83
Check
,F901 I901, I904,
F902 D901.T901
Check
Ucom（I002）
etc
Check
Q944, S903
R907
NO
YES
Does raster
E941.E943.E944
D954.D943.D941
YES
YES
Are Voltages
normal?
YES
Q777, QH01,
T701, TH01
etc.
DP65
Check