This Proton WT-3650 television is about eleven years old. The CRT has a 16X9
aspect ratio. The symptom was that the power relay would just click, click,
click, upon power on. I found and replaced two shorted diodes in the
switching power supply. I also checked for cold solder joints and bad caps.
None of the caps was even close to being out of spec.

Now the picture and sound work fine but occasionally there will be a bright
flash on the screen. As it warms up, it gets worse. Sometimes the picture
will just come on as though the screen voltage were turned way up and you'll
see retrace lines. I've tapped and jiggled all the boards but can't seem to
find anything that will make the problem appear or disappear (depending on
which state it is in) with a tap of a screwdriver.

Does this sound more like a CRT problem, an intermittent flyback, or
something else?

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA