My Hartke HA5000 blew a fuse when the power cord got pulled out of it accidentally. No problem. However, finding 8A glass fuses here in the UK wasn't easy - I found three at a friend's house. Old as hell. One didn't work, the other blew as soon as I turned the amp off and on again, and the third was fine till rehearsal last nite when I turned the amp off then on again. However, I've been turning the amp on and off with the power switch on my power conditioner - basically the amp is turned on then the cord is plugged in. D'oh.