Asi 294mc pro: Bands on photo when fan is on

giuseppe2308

Hi, I have a problem that I detect in my asi 294mc pro, regarding some bands that can be seen in the photos.
The problem occurs when I turn on the fan for cooling.
In these 2 images you can see a dark of 120s, one with cooling at 0°C (fan on), and the other without cooling (fan off).
Unfortunately these bands are also in the final image after stacking.
What could be the problem??

Corsair

Could you also post the final image after stacking that also shows the bands?

I've only ever captured darks with the fan on for my 294MC Pro and they look like the fans on dark you posted.

I use Live Stacking (for EAA) and don't recall seeing those bands in the final image.

Tech@ZWO

Corsair
The banding noise is usually caused by USB or power, you can try different USB cables or powers.
Or try to stack more frames or try longer exposure.

Why it is not obvious with the cooler off because higher dark current noise covers up the banding noise.

giuseppe2308

Hi, I tried with a new usb cable, I tried 3 other 12v 5a power supplies to power the camera, but unfortunately the horizontal bands are always there.
Even when I'm stacking multiple photos, the bands always show.
This is a m97 80x30sec light, 30dark, 30 bias, 30 flat image
One thing I've always noticed since I bought this camera 3 years ago, is that when the fan is powered by the asi air or when it is connected to a power supply (12v) independent of the asi air, touching the case of the camera feels a slight tension. If, on the other hand, I power the camera with a 12v 5a battery, this voltage is not there. Could it be that this voltage over time has damaged the sensor? Because these bands are more evident in this last month, while they weren't seen before (I put an image of a dark made last year)

2XPdo735

Hi @giuseppe2308 I'm having the same problem - did you ever make any progress with this issue?

Tech@ZWO

2XPdo735 Could you share some pics? how about the dark frames?