ASI2600mm sudden Amp glow??

Not sure what would cause that. The only issue I come across is the oil-leaking issue for the 2600 series.
But that wouldn't create such a gradient, and wouldn't be visible in the darks.

A gradient could be light leak, but I doubt it since you've taken it away from the imaging tray.. so.. doubt it.
unless something internally got knocked in some way.

Best I could suggest:

- replace USB cables 
- try a different power supply
- update any drivers/software
- perhaps try a different computer/storage

Since it's coming into the darks, I would guess it's more likely an external/software/firmware/reading/storage issue, and maybe not a sensor or camera issue. And it's not impossible for cables or storage to have degraded over time and causing issues. You'd be surprised how much can be ruined by a low quality cable. 

Obviously it's possible that those steps won't do anything, but it's where I would start. 
(if you haven't tried these things already) By doing those steps, you can, at the ver least, rule some of it out to try and pinpoint where it's coming from.

I agree with Roger's assessment. It looks like light leakage into your image train. I had the same problem last year. Dark room imaging would be rather easy to rule that possibility out.

It really does look like a light leak. I know you removed the camera from the scope, but that doesn't rule out light leaks. Try taking a dark:
- With a metal body cap on the camera (plastic sometimes lets through enough IR to be problematic); you can use a double leery of aluminum foil if necessary
- Put the camera somewhere dark and reasonably cold so the cooler doesn't have to work too hard to hit reasonable nighttime winter temps. A refrigerator works well. The rubber gaskets around the refrigerator door should protect cables from being too badly squashed

If the gradient is still there, there is something wrong with the camera. If not, you can start narrowing things down.

What does a 1s dark look like. Long long time ago I had a similar issue with a CCD. It turned out it wasn't sitting properly on the cold finger. Just an idea.

How does an uncooled dark look then?

Sean van Drogen:
only saw this once with my ASI183MM when it could not reach the set temperature during the summer

Interesting Sean,

when I was imaging I had my cooling set to -10 Celcius but the outside temperature was -14C. I didnt think to cool it below ambient temp, I wonder if this may be the culprit...would the system try to warm it up creating this glow? Have to do some digging in on this one, thank you!


Dan

Well, I was just casually reading this post as my QHY168C doesn’t suffer from amp glow but the last comments really made me stop and wonder. 

Back in January I foolishly went out to image the Cone nebula with the ambient temp at -35C (!) and due to brain freeze was trying to set the camera to -25C. The end result was a huge light blob at the bottom right of the light frames that never happened before; I could see the QHY fighting trying to set the temp and never getting there; I suspect the warming/cooling seesaw may have caused the light glare. Not sure it is the same as what Dan has but just throwing it out there.