Trouble Shooting - Hitachi C47-WD7000 Service Manual

TROUBLE SHOOTING

(1) No raster and no power (How to check LED's Diagnosis)
No
Raster
at pin(13) of PPS1
Is click sound
of Relay heard?
Check
Is Voltage at
RP03, RP04,
pin(1) of IP01
NO
RP05, RP06
more than 1.3V?
Has Fuse FP01
blown?
Check
Replace FP01
Is Voltage
NO
5.2V?
(Power Supply Unit)
YES
NO
(Power Supply Unit)
YES
(Pow Def PWB)
YES
NO
(Pow Def PWB)
YES
IP01, QP01,
QP02, RP11,
RP12, RP13
etc.
Is Voltage
at pin(16) of I004
3.3V?
(Signal PWB)
YES
Is Voltage
at pin(59) of I004
NO
"H"?
(Signal PWB)
YES
Check
Q018, Q021,
etc.
Replace U901
1.Turn OFF
the power SW.
2.Wait for 3 seconds.
3.Turn ON again after
several seconds, and
observe green LEDs
carefully.
Check
Replace U901
Appear with (47) and (44)
NO
Check
IY04 pin(37)
-H out,
IY04 pin(31)
NO
I2L_Vdd
etc.
Check
T702, R748,
R730
NO
etc.
Check
15
Check
IC101,DS101,C105,
PC102,ZD101,T101 etc.
NO
Check
I004
(Signal PWB)
Are 2 Green LEDs
NO
turned OFF at the
same time?
(Pow Def PWB)
YES
(Power Supply Unit)
Does raster
Of PPS1 shorted?
Find LED(s) that is
Turned dark or OFF
YES
Earlier than the other.
Is base Voltage
Of Q709 normal?
(Pow Def PWB)
YES
Are Voltages
At both ends of T702
(primary side)
normal?
(Pow Def PWB)
Check
YES
SW+115V line
EP02, DP40,
DP34, Q777,
Q777, QH01,
QH01, Q701,
T701, TH02
TH02, T701
etc.
etc.
Check
I013, I004
(Pow Def PWB)
Check
SW+28/-28V
line
EP01, EK01,
DP30, DP31,
DP50
etc.