Hitachi DV-DS163E Service Manual page 31

Details of Servicing and Troubleshooting > Troubleshooting
No SW_12VG
NO
Is Vcc (14V)
supplied to Q165 Collector?
YES
NO
ZD152 and Q165 Base :
Approx. 12.5V?
YES
NO
Is Vcc (33V)
supplied to Q160 Emitter?
YES
NO
Q160 Base :
Approx. 0V?
YES
NO
Q166 Base :
Approx. 5.3V?
YES
Check Q166, and
replace if necessary.
No 1.8V
Is Vcc (3.3V)
NO
supplied to Q159 Emitter
and IC154 Pin1,2,8?
YES
NO
Q159 Base and IC154 Pin3 :
Approx. 3V-3.3V?
YES
Check IC154, and
replace if necessary.
Check D124
on SMPS P.C.B, and
replace if necessary.
Check Q165, and
replace if necessary.
Check D126
on SMPS P.C.B, and
replace if necessary.
Check Q160, and
replace if necessary.
Check SW_5.3VA.
Check 3.3V
power supply.
Check Q159, and
replace if necessary.
3 - 11
No SW_FD(+)
NO
Is Vcc (FD+)
supplied to Q163 Collector?
YES
NO
R184 and Q153 Collector :
Approx. 12.5V?
YES
NO
Is Vcc (5.3V)
supplied to Q153 Emitter?
YES
NO
Q153 Base :
Approx. 0V?
YES
Check Q153, and
replace if necessary.
No 1.25V
NO
Is Vcc (2V)
supplied to Q154 Emitter?
YES
NO
Q154 Base and IC154 Pin4 :
Approx. 2V-2.5V?
YES
NO
Is Vcc (3.3V)
supplied to IC154 Pin1,2,8?
YES
Check IC154, and
replace if necessary.
Check D121
on SMPS P.C.B, and
replace if necessary.
Check Q163, and
replace if necessary.
Check 5.3VA
on SMPS P.C.B.
Check the STANBY_H
signal from IC701 Pin47.
Check D155, and
2.5V power supply.
Check Q159, and
replace if necessary.
Check 3.3V
power supply.