Can get pretty high brightness but only low contrast ?! - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 2 Old 09-15-2012, 03:54 PM - Thread Starter
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Hi. I have this very old CRT TV from 89/90 era that has developed a too dark image but I don't think it's the usual tube wear stuff. If I crank the brightness to maximum I can get a very bright white screen and I mean very. The problem is that at those levels the image is practically completely white and when the brightness is set to a level that allows blacks to be black the contrast is pretty low and image is dark, even if I turn it up to 100%. Everything I've read regarding tube wear states that image is dark even with brightness set to very high levels so I'm guessing it must be something else.
By the way, I've already taken the TV to a local technician who told me the TV's tube is worn out but I don't think thats true, for the reasons stated above, at least it's not worn out in the usual way so maybe it's possible to correct that.
Another thing, colors are pretty weak too, maybe it's the individual color amps but that kind of surpasses me. Also, I've located a service manual and took a peek but it's too much for me. TV seems to be almost totally digitally controled...
Any help/hints appreciated.

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post #2 of 2 Old 09-16-2012, 10:22 AM
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Sounds like a couple service menu or hardware adjustments could bring it back. I saw a similar issue on a more recent jvc tube, the brightness had to be cranked up in order to remove the black crush and it was still incredibly bright. I believe its an error in the grayscale near black where there is little seperation in the black and dark gray shades leading to an extremely uneven grayscale. I'm just learning all this stuff myself so I can't give you any concrete instructions. I can tell you that you should ask around the forums about incorrect g2/screen control adjusment leading to severe black crush, THE ADJUSTMENT CAN BE VERY DANGEROUS so for gods sake DON'T ATTEMPT IT YOURSELF until you've heard from someone on here who knows more about it.
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