These may last only a fraction of a scan line or much much longer.
|NotTaR of Television Sets : Occasional brightness flashes
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<< Picture fades in and out |
| Excessive brightness and/.. >>
This could mean an intermittent fault in a variety of places including
the video circuitry and SCREEN power supply:
- Brightness circuitry - SCREEN, master background or its power supply.
Could be in or around flyback or focus/screen divider. Could perhaps
be in the CRT, but probably less likely.
- Video amp before or at chroma demodulator - since after this point, you would
most likely get colored flashes since only one of the RGB signals would
likely be effected.
If you get it from all sources, then tuner/IF is ruled out.
Suppose you just have no signal to a direct video input. What do you
get? If you still get flashes, it should be real easy to monitor either
the video outputs or SCREEN supply (with a HV divider on your scope) for
noise. Then trace back to power or noise source.