# CRT HDTV picture breathing, black not black!



## Miles99 (Feb 6, 2010)

Hi, My Sony KV-27HS420 has developed a problem with the picture. I found that during bright spots(helicopter spot light filling screen) the picture "breathes" gets bigger then shrinks. As well, on the unused inputs the screen used to be perfect black, now the screen takes on a green tint, seems to bleed from the input label, covering the screen with a green tint. I get these problems on the SD inputs, but when I play a movie off the computer, the letterboxed screen shrinks by 10 to 15 %. I think it may either be a leaky cap. or on of the regulators? I would like to get this fixed, I payed very little for it and would hate to have to buy another one, money is a premium these days. Thanks for any help offered, Miles P.S. I have downloaded the service manual but find it hard to read on my 17" monitor


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## ebackhus (Apr 21, 2005)

This is an unhappy side effect of CRT technology. The symptom you're describing sounds like the brightness is set a bit too high. It happens on anything CRT from telvisions to computer monitors due to the way CRT technology works.


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## Miles99 (Feb 6, 2010)

yea, I dont have the brightness cranked up, I think I will try some freeze spray on select components to find which one is over heating


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## johngie (Oct 11, 2008)

The "breathing" symptomatic of a poorly regulated EHT supply or, more likely, a failing tube. It will be exaggerated at high brightness, when the tube is trying to draw more beam current.

John


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