Color temperature and contrast on KV-20XBR

[mirayge]

I have set my 1986 Sony 20" XBR with a THX optimode DVD. It has the best picture of any CRT in my house and is used only a few times a week. My problem is that when the picture/contrast setting is reduced, the color temperature seems to go very warm. This wouldn't be a problem if every add on tuner didn't seem to have its own brightness output. Adjust with DVD recorder and watch QAM channels = OK. Watch cable DTA = washed out. Now lower brightness or contrast and everyone turns orange. Is this normal for all sets or is something going wrong?

[kx250rider]

Sadly, if the color temp is changing with variance of the brightness, that's most likely a weak CRT. I think that set still has analog pots for white balance setup. They should all be on the CRT socket board.

A quickie procedure to try to set them:

Turn the color all the way down, and turn to a dead channel (snowy screen; not a black screen).

Use a plastic diddlestick screwdriver to set the red, blue, and green background (bkg or cutoff) pots to about 1/3 of the way up from the left (as you're standing behind the TV). Set the drive pots to middle. Look at the screen, and if it's totally black, turn the G2 pot (lower of the two on the flyback transformer) VERY VERY slightly up, until you see the vaguest hint of light of one color. Which ever color that is, turn the other two background or cutoffs slightly up until you have as close to a dark gray screen as possible. Now, turn the brightness and picture up most of the way, and see if the screen has turned to a non-black & white snow... If it's untrue, adjust only the drive controls to balance the whites, and watch the darker areas in case those change from gray. If they do, you can slightly re-touch the cutoffs accordingly, but it's easy to throw it all off. Don't be afraid to do the procedure a few times. But DON'T UNDER ANY CIRCUMSTANCES, turn the G2 pot on the flyback up any more than the tinyest bit, as that will speed up the ruin of the CRT.

If, after you are confident that you have done your best to the the setup adjustments set, and it still loses white balance from dark to light scenes, you probably need to find another set or another CRT for it.

Charles

[mirayge]

Thanks for those clear instructions Charles. I'll probably just wait for it to get weaker as there is plenty of adjustment left. Also, this tv is high up on a wall mount for watching from bed in the spare room and hard to move without dropping. The only use it gets is when someone is sick or the kids are over and want to play old video games. I guess I'm mean for telling them to turn it off when a game is paused forever, but this old set may make it to 30 with care.