Sony monitor - intensive screen flashes after power on

I would say it maybe the last repairer may have not replaced the earth connecting leads to the same points on the matel subchassis, or perhaps may have removed the aquadag which is a bare braided strap that runs around the back half of the (crt) tube. sounds like it is a static discharge at inital start up. Wonder if it has happend from when you got it back from repair or only recently. In any case still sounds like disharge to me. they run under 29kv so it is a lot of initial charge.

Sounds like a short in the CRT, ie a grid short on the blue gun. If it gets to the point where it happens all the time (which it probably will) then the CRT could well be scrap. Replacement is not an option.

CRT shorts can sometimes be cleared by a CRT rejuvenator, but that would mean putting it into a TV repair shop and hoping they have a rejuvenator with the right socket for your CRT. It may not be worth it financially though.

Dave

It has happened recently. The repair two years ago was (typical) FD Trinitron brightness problem where you can not set brightness down and there were also few diagonal lines visible on the screen. I brought it to the Sony repair center where they fixed it and adjusted the screen focus and convergnce so the picture is excellent now.

It seems I can live with the problem, sometimes the monitor even switches off during the initial flashing sequence.

I know LCDs are current technology but if there were 19" with 1600x1200 resolution or better ...

I see, I can expect it will become permanent problem (not on startup only) after a while ?

Petr.

It's likely the CRT will fail rapidly, depending on the frequency of the flashes. The more it does it, the more damage the blue electron gun will endure, until it fails altogether. There's nothing you can really do about it I'm sorry to say. Even if the intermittent short could be blasted out, which they sometimes can, it's doubtful whether the CRT will last much longer anyway.

There's also the possibilty of damage to the video amps due to the flashover, which could mean either no blue or blue full on, both of which would render the monitor unusable.

Dave