It certainly sounds like a thermal problem. I assume you have nothing blocking the ventilation holes.

Does it cut out if you leave it switched on but with the master level control at zero?. You could try testing by leaving an input signal attached and then winding up the master level control at ten minute intervals just enough to hear whether it is still alive, and then down again if so.

One thing I did not say in my previous post is that your Stagepas unit is presumably still under warranty. Assuming you haven't found anything in your usage such as obstruction in the ventilation, the problem you describe should be dealt with as a warranty issue.

It would be useful to whomever you bought it from to know how to reproduce the problem, so it could be worth experimenting a bit more to see if there is anything that would help in tracking down the cause of it cutting out. However, I would not spend long on it, and instead pursue a warranty return.

Thanks for the info, we tested it again a couple days ago and of course it worked perfectly, so will keep monitoring it to see if we can make it happen again, but as of now its working.