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Troubleshooting
CPQ-C1786FNSL/T (FS7550/V7550)
6 Troubleshooting
6-1 No Raster
Check voltage of
cathode, heater,
Grid 1, Grid 2, etc.
Check I401,
I703, R719, C741,
R4F6, R4F5, R4C4
Check
I801, R807,
R808, Q801,
Q802, ZD802,
VR801
Check D801,
D802, D803,
D804, T801,
R804, F801
Yes
No
Normal
(56 V, 31.5 kHz)
Short Circuit
at load?
Measure
voltage of B+ at
T402 pin 2 on
PWB-MAIN
No Raster
0 V
High
(75 V or more)
Check DC
B+ line, Q451,
Q402, T402
Yes
Check voltage
of C808
No
