Otrona Attache power supply woes...

You mean that the reference voltage is still far too high? OK, the first thing to do is to check your voltmeter. I doubt that's the problem, but you can go round in circles if you're looking for a fault that's not there :-). I'd measure the +5V line in some of your (working) computers, if those read close-on 5V, then the meter is OK. Assuming you havea good voltmeter, nect remove the chopper PCB from the Otrona PSU (from the diagram this looks to be a separate unit). This will prvent the chopper sprinng into life when you're working on it, and even more importantly it'll mean the chopper (and other things) can't be damaged if one of your tests causes the controller IC to give it the wrong drive signal. Assuming Vref is still too high. desolder one end of each component connected to Vref -- IIRC that's the '+5R' signal on the scheamtic, power up and test the voltage on the Vref pin of the IC after each one is lifted. Once this goes back to normal (and you'd better hope it does), solder them all back _apart from the last thing you lifted_ and check that Vref is still reasonable. If so, then troubelshoot around the last part you removed. -tony