Pleased that PS2 works now. I'd still open up and have a look as I advised. If there's no obvious sign to alarm you (and a burn smell location would linger for a while), then it is possibly OK. But I can't give you definitive advice that the PS2 is OK.

As a guide, in my (don't rely on it) opinion, 5V circuits don't produce a burning smell; it would have to draw more current than the mains could supply. 50V and upwards can.