I recently tried to fix a '68 Super Reverb for a friend (my first foray into amp repair). Turns out it was a bad driver tube, but I found all sorts of other problems so I gave the amp a full cap job and replaced the plate resistors per an article I found from Hoffman amps. When I finished and turned the amp on (still on standbye), it made a very loud static sound. After a minute the sound went away, so I flicked the stanbye switch and poof, one of the bypass caps I replaced exploded. I had put in a bias probe to check the bias, and noticed that one of the power tubes wasn't glowing. Turns one of the tabs in the socket was bent so one of the tube pins wasn't seated properly. Could that cause a cap to explode?