I'm trying to debug a friend's AMP6 audio amp kit. It seems that an electrolytic smoothing cap on the output of a 5 V regulator has been soldered in backwards. This seems bad, but the component is going to be a little tricky to desolder because of its physical location. Because of this, I'm trying to be certain that this is the problem before attempting the job.
Before it explodes, how does a backwards cap behave? Like a 100 ohm resistor?