HD CRT Widescreen Sony CRT dieing.
 

I think my HD CRT is dieing

Sometimes I will get a bright flash on a cold start(has not been on in a while.)
sometimes it will shut off when it happens.

I bought it used in 07 or 08 and has about 8,000 to 10,000 hours that I put on it since.


Total hours about 14,000 to 16,000 hours

also it's slightly out of focus when it's warming up normally corrects it self when the quick bright flash happens.
It has one HDMI port

I hate LCD's as they do not have the same contrast and brightness the CRT has and they never will because of what they are made of.
also the color is off once off center viewing axis even if it's a 178x178+ viewing angle type of screen.

Plasma is not my cup of tea uses way too much power and makes too much heat
Plus I hate the Green frames that is introduced by the screen were the whole screen looks green for a split second.

It could be a transient short in the CRT, which could act this way for years, or it could blow the power supply sooner.... I'd recommend going in Craigslist and picking up another Sony wide WEGA CRT set now, while they're free, or nearly free in great condition...

Charles

Sounds like flyback/focus divider failing. The CRT on this set shows color tinting when it starts to fail and then ends up not drawing enough current to get the set out of video mute. I don't know if that flyback assembly is available or not. I would not use a generic replacement if one is available since they can cause Sonys to give all kinds of weird symptoms. The screen circuit is in the flyback too (if I remember right) and that could cause the flashing.
Have you ever changed the MCZ3001DB IC's in the power supply? These are common failure also but they cause the set not to start sometimes or just go dead. They won't cause the symptoms you are having but they can make you sratch your head a good bit!
Also, does yours use the fine pitch picture tube?

KV-30HS420
Hi-Scan 853x1080i




If I let it warm up then change it to max brightness and contrast the flash does not happen and is focus correct