Hey folks, I got a weird one for ya!

I've bought this Dell Trinitron P992 on eBay early this year and the seller performed a WinDAS calibration on the monitor.

Ever since I started using the monitor, i've been getting a strange issue where whenever I display something with a lot of white, the screen automatically dims, so much so that it is hard to see things in applications like Quake3. When something with a lot of Black is displayed, the monitor gets really bright.

Here is a video of it in action: https://www.youtube.com/shorts/2npEqEFgb-4

Here is what I have found out so far

It is not happening to the monitor OSD, Video with OSD here: https://www.youtube.com/shorts/38Ijs4Q5bj8

It is not the PC, OS, or GPU: Confirmed by trying multiple GPUs, tried Windows 10 and Windows 98, tried different CRT and LCD on the same machines and the issue does not present itself on those screens.

This is not the famous "breathing" issue on Sony monitor. As you see in the videos, the image is not moving, getting bigger or smaller. Its just changing brightness (or maybe Gain?)

Since I didn't do the WinDAS adjustment, i'm wondering, could some setting in WinDAS cause this?

I don't know if the seller saved their old WinDAS settings, I am reaching out to find out. Is there some way I could get default WinDAS settings for this monitor from the community?

I am in the process of acquiring RS232 to TTL adapter so I can try WinDAS myself.

Could this be a hardware issue? Could bad caps cause this problem?

I have searched and searched but no one seems to have reported this strange issue. I am at a loss at this point...