#1
Hi i have recently had my amp go out. This happend when i was turning in back on to go for jam 2 in my session,...I saw the indicator light turn on i then saw it go out and then nothing......So i took it apart and i realized there was a burnt looking fuse....f203 slot/ 250 fuse-......Well today i put a new fuse in and when i went to power the back up...i got nothing...i then realized that the fuse was kind of burnt looking...i know it was clear when i had just put in it......I then figured will i would take it out and try onother new fuse...this one was not glass and is white put it in checked my solder Job over...Looked good, though still no power.................................................I was wondering if anyone might have an idea of what this might be or an idea at what to look at next?...My thoughts are maybe ive over looked something else that is currently blown?...The first replacment fuse burnt up to so maybe theres something causing that....I have checked my main fuse i think it is good...Is there really a way to check a white coated fuse?...Any help is very much apperciated.....Thanks!
Last edited by mrb_1986 at Nov 9, 2011,
#2
The only way to check a ceramic (white coated look) fuse is with a Volt Ohmeter. You need to check the fuse for continuity. A VOM will allow you to do that.

The general rule of thumb is if the fuse blows, replace it. If it blows again, it's time for professional service. To continue installing more fuses will only cause additional damage as more components become defective. Since this is a tube amp, here's what I'd try: Remove all the tubes. Make sure you mark them as to their location. A Sharpie marker works great here. Install a new fuse and try it again. If it still blows, then it's possible you have a biasing resistor issue, transformer issue or something else causing it to draw a lot of current. If it does not blow a fuse, then it's likely you have a bad tube. Chances are it would be a bad power tube.