So I was playing with my band today. For forty-five minutes, it sounded great, but then all of the sudden I noticed I wasn't getting any signal from my amp. So I started fidgeting with the cables, thinking one of them had shorted. Stupidly (probably because I was embarrassed and on-the-spot), I left the amp on while strumming to see if I could get a signal, to no avail. I later found out that the speaker cab input jack had a loose solder joint. So in effect, I had been strumming into my amp with a no load situation. After soldering the joint, everything sounds fine again. Even so, do you think I could have caused any premature, possibly undetectable (as of now) damage to my amp? Or am I just extremely lucky?