LG OM7550 - Page 47

3-26
ELECTRICAL TROUBLESHOOTING GUIDE
No -5 V
Check or replace 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
Is the D959 normal?
YES
YES
YES
No output AMP gate line
Check or replace R952.
Check or replace D952, D959.
Check and replace IC952.
Or check line of MAIN PCB is
short or not.
Is the VCC
13 VA supplied to IC952
pin1 to pin3?
NO
NO
Is the R952 normal?
YESYES