LG CM9730 - Page 44

3-27
ELECTRICAL TROUBLESHOOTING GUIDE
YES
YES
YES
No output VFD
Replace R968.
Replace ZD951, ZD952.
Replace D959, D957.
Check line of FRONT PCB is short or not.
NO
NO
NO
R968 normal?
ZD951, ZD952 normal?
D959, D957 normal?
No -5 V
Check or replace R965, D959.
Check P_CTL from μ-com.
Check or replace Q953, Q957.
Or check line of MAIN PCB is short or not.
Check or replace Q951.
Is the
VCC -7 VA supplied to IC953
Pin2?
Is there
‘H’ signal at Q953
Base?
NO
NO
NO
R965 normal?
YES
YES
YES