My guitarist lent me his old amp and guitar in exchange for my old amp and bass. He said the amp hadn't been working since one day when he turned it on and heard a loud pop. I figured he just blew a fuse, no big deal. So I took it home opened it up and sure enough, the fuse was fried. So I replaced the fuse, turned it on, and it blew the fuse again. Any ideas on what the problem could be? The amp is a Peavey Studio PRO 50 (SS), and the fuse is a 2 Amp 250 volt fast blow.