Electrical Troubleshooting Guide; Power Check Flow - Zenith DVB611 Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

1. Power check flow

A.
No 5V
Is 3.4VA section working?
YES
Is 5.6V present at collector
of Q126?
YES
Replace Q126.
NO
No 3.4VA
Check FR101
Is there a DC voltage at
Cathode of D105 or D107?
NO
Replace IC101.
3-2
B.
No 3.4VA.
NO
Is 3.4VA section working?
YES
NO
Is 3.4V present at emitter
of Q121?
YES
Replace Q121.
YES
NO
Check D105/D106/D107/
D108 and replace.