The other day at band practice the guys that live upstairs from where we practice thought it would be funny to pull the fuses out of the fuse box and cut off all our power. They did this a couple times and I started to worry about my amp. Can this cause damage to amps? I'm guessing it can, but want to make sure. And if it does, exactly what can go wrong?
CUTTING power shouldn't be a problem. It's just like turning off the power switch. Turning it on and off quickly, repeatedly, however might be a problem. I say tell the neighbors to bug off and let live.
I'd be more worried about when the power came back on, seewuddamean? Turn your amp up halfway, then turn it off. Then, hit an open E and turn your amp back on. Now, seewuddamean? Tell those jerkies, "Buzz off, or I'm gonna give you a DP Custom enema!" EDIT: Seriously though, I would report their behavior to the landlord or building super. You pay rent there (or your drummer or guitarist does), they should keep their mitts off of your fusebox.
I don't think the guys will give us problems any more. They were just being drunk frat boys. Plus we showed them we weren't afraid to introduce them to our little friend Mr. Crow Bar. I just wanted to know if I should be worried if it ever happens again.