It sounds like when the speakers were being swapped a connection was left open and all the smoke came out. Old timers know that when you let the smoke out, electronic devices quite working. Some newer stuff has such small quantities of smoke in them that it's easy to miss seeing it when it gets loose and goes away, so youngsters may not be familiar with the rule. Older stuff had enough smoke in it that it was usually obvious.

(In other words, I think we need a little more info. gnu may be able to give us some more clues in the morning after a good night's rest, if the hangover isn't too bad at wakeup time.)

John