I turned on my ST-70 the other day and the fuse popped. I replaced the fuse and watched the tubes when I turned it back on. Nothing odd happened, none of the tubes are arcing or glowing weird and the amp played fine. That was about a week or so ago. The amp has worked great since then. When I turned it on today, the fuse popped again. I changed it and watched the amp for anything weird and once again, there was nothing and the amp appears to be playing normally. Nothing is getting hot and there isn't anything that I can find burned. Has anyone else experienced this? Is there something specific that I should be looking for that is causing the fuse to pop?
Any help is appreciated.