So this is even more strange than that. I run the amp, runs fine, it is noisy/crackly though at times. The fuse does not blow when the amp is on. Not when I use it or even if I leave the amp on. As a test, I have been letting the amp run for a number of hours today. I turned it off with the power switch, not using the "standby" and it powered up just fine. It is a Fendery type head. Last night, I was swapping preamp tubes and I was using the "standby" switch. There is a loud pop when I use it. So, I finish playing it and shut things down for the night not touching the standby switch. This morning I come in to power it up and no go. No light, fuse dead. This has done this since I got it second hand here about 3 months ago. The amp did come with a problem in that it drops in power and begins to distort, though run, if I put boost boxes of any sort. Even if it is a unity gain boost. Really scratching my head. Amp sounds beautiful tho!