bdevis I tested different timing with different gain but i have got always the same result.
I can't quite read the tiny screenshot that you linked to, but it seems like your Max ADU (lower right corner of the screenshot) is way low (three digits?), but then, so is the exposure time (appears to be 0.01 second).
If this were a night picture, it is what you would expect (especially if you are not perfectly focused).
Increase your exposure to a few seconds at a minimum to see stars appear. By 100 seconds, your Average ADU of the sky background should also climb to over 1000. (That being said, I am able to see Deneb in bright daylight 1.5 hours before sunset with a 0.1 second exposure on an ASI2600, a narrowband filter and a perfectly focused OTA.)
Unless you are using a very heavy filter (narrowband or neutral density filters) or have a lens cap on, the Max ADU in daytme (even indoors) should saturate the sensor (ADU of over 65500) with just a one second exposure (even when no focused). If you are not seeing that, try connecting the camera to a computer program such as ASIcap to check if it is a hard camera failure.
Can you move your ASI120MM over to the main OTA just to check that there is nothing obstructing the light in the main imaging train?
If it is a night picture, an out-of-focus image can also show what you posted. The flux of an unfocused star could be spread over a hundred, or multiple thousands of pixels for the severely out-of-focus case, and everything will be below the camera's noise level.
Coincidentally, I am just now resurrecting a long-retired uncooled ASI178MC for use as an all-sky camera since I also have a ver. 1 ASIAIR that is not in use. The ASI178MC appears to work fine as the Main Camera in ASIAIR.
Chen
