Hi there,

I have a Marshall AVT 100 and whenever I turn it on it makes a strange whirring sound. It sounds a little bit like a tiny little chainsaw is inside it. Eventually it stops on its own or if I smash my hand on the top it sometimes makes it stop.

Anybody know what is causing this?
Ahh so there is a fan in there then. I thought it sounded like a fan that's probably covered in dust or something but I didn't see why my amp would have a fan in it.