Too bright color on some screens- symptom of failing CRT? (T32-2)

On my QT8n with T32-2 control, certain screens have extremely bright blue or green backgrounds that make everything all but illegible. For example, the setup screen has a very bright green background, while the simulation screen is extremely bright blue, the text is almost impossible to read and any wireframe graphics are not visible at all. The position, parameter, diagnostic and other screens look fine. I played with the brightness pot on the front of the cabinet and the two screen/focus pots on the back of the CRT but it didn't change this problem. Some photos are attached (ignore the dark horizontal bands, just an artifact of the photo).

I'm ready to buy a LCD screen retrofit if this will solve the problem, but am a little wary of wasting my money if it is something else. Most stories of failing CRTS seem to be sudden complete failure or gradual darkening. Anyone else seen this? Maybe there is some setting/parameter I need to change?

Check for background/foreground color parameters. Also check if you have a contrast adjustment. The selected colors are poor choices even for a brand new monitor.

My choices would be:
1. Green on black.
2. Black on eggshell.
3. Red on black.

Green on black is the easiest on the eyes.

Can't find any background/foreground color parameters in my parameter list...
I dont have complete set of manuals, so I'm missing whichever one explains the display card, anyone had to replace one on the T32-2 before and know which one to check out? I attempted tracing the display signal cable but couldn't get far without tearing apart all the wiring looms.

sudsy55 said:

I think its the 724 card on the T and M32's but don't quote me on that

Click to expand...

Yup, googling "MC724" I was able to find a M32 manual that indicated the MC724 was the display card, then looking at my own machine I traced the CRT signal cable back to that card. Mine has a MC724B-1. I ordered a good used card from ebay for $50, will swap it in and report back!

Any setup that needs to be done with this card after installation?

My screen on my old T1 went very bright and had retrace lines. Brought it to an old guy (knows CRTS) who used to have a electronics repair shop and he found a couple capacitors that were bad. $5 in parts and $30 to repair and it was like new. Cant hurt to check for bad caps. The ones in mine were bulged out in the bottom, I probably could have found it if i knew what to look for at the time. Ill have a closer look next time around.

Swapping the MC724 board fixed the issue! All screens look normal and now I can see the wireframe graphics. For what it's worth, my original board was a MC724B-1 Rev. C and the replacement used board was MC724B-1 Rev. D. Pretty good feeling to have it be only a $50 board swap rather than a multi-hundred dollar screen retrofit.
Thanks for the help everyone!