ASIair Pro disconnects

propus

On my last outing my main camera would disconnect from ASIair frequently. This happens in Live stacking, at the end of an exposure, and before loading, More frequently with longer exposures. Live will hang up, and nothing is loaded. I have to exit live, re-install the main camera, switch it on, and then switch the cooling back on. The guide camera doesn't disconnect; It is connected to the main camera USB. I can not make 600sec exposures work at all. 300sec usually work, but not always. Is this a known problem?
Main camera ASI294 MC Pro
Guide ASI178
Android
Live stack with cal frames
guiding with dithering

Tech@ZWO

1.What is your ASI294 MC Pro external power supply? Is it DC 12V?
2.Have you tried connect ASI178 to ASIair Pro?
3.Is there other device connected to the main camera USB except guide camera?

propus

My 294 is powered from the ASIair which is powered from a 34Ah 12V AGM battery.
No, should I connect the guide camera directly to the ASIair pro? I can try that tonight.
No other devices.

Tech@ZWO

propus
Please connect DC 12V.

propus

I have a connection from the ASiair power out, to the 294 DC in. The power is switched on in the software. The cooling works, so it's getting some power.
I will check my wires, connections, and voltage.
In the meantime, I am waiting for a clear night to try connecting the guide camera directly to the ASiair.

propus

Voltage from ASIair to camera is 12.5V
Problem occurs with or without guide camera.
It seems to only happen at 600sec. (I've never tried 1000sec)
I believe it only happens when I have my 600s dark frames file selected for live stack. Flats & bias selected don't seem to have any effect. A corrupted file perhaps? I will try to re-shoot my 600s darks tonight when it cools off.

propus

I re-shot my 20x600s dark frames. NO HELP
so unlikely a corrupted file?
I re-shot 5x600s darks. still no help.
it doesn't seem to correlate to stacking flats & bias, only darks.
So any ideas? Please? I'm at my wit's end.

Tech@ZWO

Have you tried powered seperately( not from ASIair )?

propus

I measured the voltage to the camera, but I haven't tried an independent source. I'll give that try tomorrow night.
Thanks