Hitachi DV-DS163E Service Manual page 29

Details of Servicing and Troubleshooting > Troubleshooting
(2) SMPS Circuit (on I/O P.C.B)
No 12V
NO
Is Vcc (14V) supplied
to Q164 Collector?
YES
NO
ZD151 & Q164 Base :
Approx. 12.5V?
YES
NO
Is Vcc (33V) supplied
to Q162 Emitter?
YES
NO
Q162 Base :
Approx. 0V?
YES
NO
R171 : Approx. 5V?
Q156 Base : Approx. 0.7V?
YES
Check Q156, and
replace if necessary.
No 5.2V
NO
Is Vcc (5.3V) supplied
to Q151 Emitter?
YES
NO
D153 & Q156 Collector :
Approx. 0V?
YES
NO
R171 : Approx. 5V?
Q156 Base : Approx. 0.7V?
YES
Check Q156, and
replace if necessary.
Check D124
on SMPS P.C.B, and
replace if necessary.
Check Q164, and
replace if necessary.
Check D126
on SMPS P.C.B, and
replace if necessary.
Check Q162, and
replace if necessary.
Check the PWR_CTL_H
signal from IC701 Pin43.
Check 5.3VA
on SMPS P.C.B.
Check Q151, and
replace if necessary.
Check the PWR_CTL_H
signal from IC701 Pin43.
3 - 9
No 5VT
NO
Is Vcc (5.3V) supplied
to Q155 Emitter?
YES
NO
D152 & Q152 Collector :
Approx. 0V?
YES
NO
R180 : Approx. 5V?
Q152 Base : Approx. 0.7V?
YES
Check Q152, and
replace if necessary.
No 33VT
NO
Is Vcc (33V) supplied
to Q161 Emitter?
YES
NO
Q152 Collector :
Approx. 0V?
YES
NO
R180 : Approx. 5V?
Q152 Base : Approx. 0.7V?
YES
Check Q152, and
replace if necessary.
Check 5.3VA
on SMPS P.C.B.
Check Q155, and
replace if necessary.
Check the TIMER_H
signal from IC701 Pin44.
Check D126
on SMPS P.C.B, and
replace if necessary.
Check Q161, and
replace if necessary.
Check the TIMER_H
signal from IC701 Pin44.