CRT Colors & Wear?

[lnx64]

Originally Posted by freakaftr8

Hey there.
Well after seeing those second set of pictures I would say you have a CRT issue of some sort. The color looks soft and the convergence looks off. Has the tv been dropped?

Shawn

I'm really not seeing this.

I just think the finger is being incorrectly thrown here.. Sure, I'm a newb when it comes to CRT diagnoses, but I've seen a LOT of Trinitrons just have soft focus and off convergence that are easily fixed.

[freakaftr8]

Some of these sets had a knob called hstat. For static convergence. Not sure if this one had it or not. It was easy for these to move. If so it could need a touch up. While in there touch up greyscale. The CRT prob has many hours on it but many hours left. It's a trinitron.

[Outland]

Hm, supposing it had the hstat knob, that solves the convergence, but what can be done about the overworking red gun?

[lnx64]

The red gun itself isn't what the problem is, otherwise you'd see it in the greyscale patterns. I think it's somewhere in the NTSC decoder.

[Eric H]

The tube may be worn but I think a grayscale touch up would help it.
It definitely looks to Red to me, I agree that a little more Green might help, assuming the tube has more green to give.

I don't know if the Drive controls are Potentiometers on this set or in the Service menu.

The service menu on the XBR's of this era were accessed by pushing a hidden button on the back of the set while powering on.

[Outland]

Originally Posted by Eric H

It definitely looks to Red to me, I agree that a little more Green might help, assuming the tube has more green to give

I think that is the key. If it doesn't, then I'm afraid the set can't give a nice enough picture for me to consider 'usable'.

It does have a primitive OSD (for volume, input, and picture only) and everything else is on potentiometers.

Here's a picture of it with the back off. Do you see anything that could be used to service it?



Another interesting point is that very red reds come out pink. Turning the hue to compensate makes the image too yellow otherwise. Very odd.

This is turning into quite a little project.

[Eric H]

The Service Menu is different than the Menu for Color and Tint etc.. it was only menat to be accessed by Service People.

IF this set uses a Service Menu it will be accessed by some Method not obvious to the user.

If it was an XBR there would be a small snap switch on that board near center bottom, not sure what others used it but this seems to be a higher end set so it might.

Look for a small button switch on that board or nearby, there will be a corresponding hole in the back cover if it's for the Menu.

Hold it down while powering on the set and it should come up in Service Mode.

If it doesn't have a SM then the controls for the Screens should be on the board on the back of the CRT.

[Outland]

Hey guys, sorry I didn't reply sooner, I had some other things to attend to.

No, I know, my point was that it's difficult to tell if the set has a service menu or service potentiometers.

I see no buttons on the back, unfortunately.

I've found that ramming the brightness up to 75-80% evens up the colors quite nicely, but red is still pushing too much. Even without a signal, the 'haze' that comes from having the brightness too high is tinted red as well. The resultant picture is still uninspiring.

What kind of control would the service menu/potentiometers give me if I was able to access them?

[freakaftr8]

Poteometers are on top of the CRT neck board. Yes they are there I can see them. Look for rdrv and turn it down a hair. Might need to tweak the r screen too.

[Outland]

Hey there freakaftr8,

I see. Didn't you say that changing color drives is only a temporary solution to a failing tube?

I wonder why B & W images don't look red-tinted to me, are my eyes playing tricks on me?

[freakaftr8]

Sorry I misread something. Yes I'll agree with others. It may not or still could be the CRT. But could be a demod issue as well. If color off is truly b&w no red hue then sounds like demod circuit. You still have a slight convergence issue but I've seen worse.

[Outland]

Yeah, the convergence issue is pretty bad too, especially around the edges. Here's a picture of the lower part of the screen:

It's supposed to be white text.

So the problems with the TV are as follows:

1) Red gun firing too much/other guns firing too little.

2) Greens are pretty dim, while extremely red reds are pink.

3) Convergence off, especially on the edges.

4) Overall brightness is a little dim.

Is it worth going after all these issues? Is anything at this point a temporary fix anyhow?

Thanks all.

[Outland]

So you guys have run out of advice!

I'm really at a loss about the pink reds and off convergence, can anything even be done about that?

[old_tv_nut]

1) with regard to convergence - this is a separate issue. You need to go through the adjustment procedure. For this you need a test pattern and the service info that gives the procedure - but you should be able to improve it.

2) With regard to the color, I think we have reached the limit of what can be diagnosed remotely with the sources you have. You don't have the experience to describe what's going on, and if you did, you wouldn't need us. As others have said, the evidence so far is inconclusive.
If you can get a color bar test pattern and a gray scale pattern to view, that might help diagnose if it's CRT, tracking adjustment, color demod chip or ???

Where are you located (roughly)? Anywhere near someone who could come out and look at it with you?

[Outland]

I see.

I can clearly display a test pattern, but I don't have the service manual. Would someone more experienced than myself know how to fox the convergence?

I'm certainly not knowledgeable about such things, but I can do my best to show the problem.

I could connect my laptop through composite and display any pattern you wish. Would that help?