LG Flatron W2234S - Troubleshooting Backlight Failures; Backlight Turn On;Off Issues

4. Backlight turn on and turn off soon
18
Backlight turn on but turn off
Reinsert
lamp wires
OK
Workmanship
NG
Replace panel
OK
Panel NG
NG
Check Pin7 of
IC it have
signal or not
NG
Check I/F BD
R509/C506
OK
Check Pin2 of
IC501, is it 1.3V
when backlight
turn on?
NG
Check
D505/D506/
D507/D508
OK
Check Pin1 of
IC501, is it 1.2V
when backlight
turn on?
NG
Check
C519/C520C521/C5
22/C523/C524/C525
/C526/D501/D502
OK
Check
Q502/Q503/Q504/D
503/D504/D510/D5
11/IC501