Hiwatt doesn't have a schematic, so that's out.
I'll ask them to do what you said but I think they're telling me it's too expensive to fix.
Not sure if they want to do any more on it.
Would it be a good idea to just take the amp back at this point on Monday and try some other tech? I do have a picture of the components on the board.
One other tech told me this was unfixable. It was badly designed.
These guys think it's the power supply.
Would the fact that the transformers are not 90 degrees to each other be a factor?
I have apicture of the components don't know how to post it.

Had some trouble figuring out how to post!
Anyway, the problem is that turning up the master volume even with the gain low will cause a dramatic increase in noise and hum. If we attempt to put the gain high and master low, we can't go much higher with the master because again we get more noise and hum.
This is with no guitar plugged in.
The amp was restored to the original values on the board(it's pcb) and 2 traces were reconnected. Supposedly the amp is grounded. It wasn't before.
Someone tried to get around the issue by killing the gain, but the problem was there.
Is this amp fixable without a schematic?
They're saying it'll be very expensive.
So if we turn everything off there is no hum.
There is also a buzzy static as well.

Took this amp in for repair and it has 60 hz hum.
I've been told the rectifier diodes might be the source of the problem,
but without a schematic the cost is through the roof.
Any ideas what the exact cause is?