Compaq CPQ-C1786FNSL Service Manual page 26

6-5 Out of Horizontal Synchronization
6-6 Out of Vertical Synchronization
Check I401 pin 12 & pin 13.
Out of Horizontal
Synchronization
Horizontal
sync present at
pin 15 of I401
Yes
Check
I401 pin 8 H. output
frequency & pin 29
waveform
Yes
Check Q401,
T401, Q402,
R424, D401
Out of Vorizontal
Synchronization
Vorizontal
sync present at
pin 14 of I401
Yes
Check
I401 pin 24 waveform
Yes
CPQ-C1786FNSL/T (FS7550/V7550)
Check or replace
the signal cable or
No
H. sync pin 41
of I701.
Check or replace
No
I401, C406
Check signal cable
& V. sync pin 42
No
of I701.
Check or replace
No
C303, I401,
Troubleshooting