Mac 512K Working!

--- Tony Duell wrote: The Mac PSU is a little marginal and should be tweaked if the load changes. How I do it is to connect a DC voltmeter to the +5V line on the logic board (for example on the mouse port). And adjust the DC voltage preset on the PSU board for a reading of 5V. I am not sure if this is the official procedure, though. --- end of quote --- What you're doing is probably fine. The "official procedure" at the repair shop where I used to work involved a special little testing adapter (available from Apple, but probably only to authorized service centers) that plugged into the Mac's floppy port and split into four wires, one of which was ground. The other three were some combination of 5V and 12V leads (I think one 12V, one -5V, and one +5V, or something like that). You'd check all three and tweak each of them to within some tolerance, and according to the service manual, if you couldn't get all three within tolerance, then you were supposed to replace the board. -- MB