I have a DT25 that I haven't had for very long. Over the past week or so it started to cut out on me intermittently after short periods of use. Initially the sound would cut out, the power would go off for about a second, then you could hear everything click back in to life and we'd be back up and running. I took it in to a local store and had a look under the hood. We felt that one of the tubes felt like it was poorly seated so we resolved that.
I got it home and it worked OK for a few hours then the problem started again, only this time just before the power goes out I get a loud momentary screech similar to feedback. It raises in pitch and then the amp dies and returns to life a few moments later.
Any clues before I take this in to a qualified repair service and spend money?