I went to show a knowledgeable friend the symptoms of the Mac Plus clicking and on switching it on it gave the start beep, no clicking, no screen (I didn't have anything in the Floppy Drive - don't know if it needs an operating system to fire the screen, having no hard drive). After taking the logic board out to free up a jammed floppy drive, reassembling and starting, the clicking is back. A few taps on the side of the power board and I get the clicks AND the start beep! I've still had no chance to test or resolder anything. Does this rule anything out, or in? It seems like there's something loose enough to be that easily disturbed. Is there a logical place to start re-soldering in the light of that strange behaviour?