LG RN7 - Electrical Troubleshooting Guide

1. POWER (SMPS)
No 12 VA
YES
F901 normal?
Replace F901 (Use the same fuse).
YES
NO
BD901 normal?
Replace BD901.
YES
NO
TH901 normal?
Replace TH901.
YES
NO
Is Vcc
(10 V ~ 18 V) supplied to
IC901 pin2?
D902 normal?
YES
NO
Check or replace D902.
Is there
about 2.5 V at
IC941 pin1?
Replace IC941.
YES
YES
NO
D951 normal?
ZD932 normal?
Replace D951.
Replace ZD932.
YES
NO
NO
D921/ D922 normal?
Replace D921/ D922.
YES
NO
Power line of main PCB is short.
NO
3-16
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ELECTRICAL TROUBLESHOOTING GUIDE