Page 25
Troubleshooting
CPQ-C1786FNSL/T (FS7550/V7550)
6-7 R.G.B. Video Amplifier Abnormal
Check or replace the
signal cable or I501
Yes
Check
waveform at I501 pin 5, 6 and
7
Check
I502 pin 1, 2 and 3 collector
voltage (normally about 70V)
& waveform
RGB Video AMP Abnormal
Yes
No
Yes
No
Replace I502
Video signal present at the
pin of the CRT R.G.B.
Cathode
Defective cut-off circuit
(DC restore) I504
Yes
Check
waveform at I501
pin 18, pin 19
and pin 20.
No
Replace I501
