Hi, I'm pretty unaware of most things amp wise, but I'll explain my problem. It seems as if my Hartke head(HA3000) isn't working. I did a gig Saturday and everything worked fine, nothing unusual happened, wasn't louder than normal etc... Now when I went to plug it in at home a few days later I get no sound whatsoever out of it. I tried different cables on everything to see if it was that, as well as trying all combinations of speaker outs to the ins of the cabinet to check if it was a single faulty connection possibly. I also tried different basses to be sure it wasn't the bass, but to no avail. The power comes on I can hear the fan moving, just no sound at all. I don't have an extra head so I couldn't check to see if it was the cabinet but that doesn't seem likely. One other thing I noticed is that even though there is no sound the "clip" light stays lit as if it's overloading signal. I don't remember this light ever being on before, at least not constantly. Anyways, she's off to the repair shop a bit later, just wondering if anybody more technical then me has any idea. Did a tube blow or something? Thanks for any info.