And it was as you stated. I swapped one from my "extra" BA and it works like a champ. thanks! And, in the process I finally looked for the NPG jumpers and found out which slots didn't have them (which made my ts-11 much happier :-) I also "tuned" the 785 supply - it was lagging around 13v. I assume cranking it up to 15 is the right thing to do. Anyone have an RA81 HDA they don't need? -brad

Oh for %deity's sake. This thing has only a handful of components. It probably took you longer to get the 'replacement' out of the other BA11-K than it would have taken to fix the original thing... I am not that 'hot' on conservation, but I do believe in replacing as few parts as possible. And that means changing a capacitor or a 3-terminal regulator, or whatever, not a PCB. Please don't module-swap classic computers (this rant has been here before, you won't change my views on it, I've seen the unpleasant reuslts all too often!). Yes, if the reason for it being low was that you'd added extra loads. No, if the reason for it being low was component failure in the -15V brick. Asjustments rarely, if ever, drift. If some voltage is out of spec then there's a reason. If it's something you did -- like adding an extra load -- then yes, you use the adjustment. But if it's just gone down while the machine is in use, you need to find out why. A dried up capacitor in the brick probably. -tony

There are many reasons why module swapping is a bad idea. The main one is that in a lot of cases you don't _know_ what the fault was, so you don't know you've fixed it. This particularly applies to intermittant faults. Then of course there's the issue of what happens if the module was damaged by a fault elsewhere in the computer (e.g. a short circuit on one part is killing a PSU regulator under particular circumstances). And the issue of revision levels (do you know the replacement module will work correctly with all others in the machine?) (Spent hours tracing a 'fault' caused by this -- it turned out that the later revision module needed a couple of extra wires on the backplane...) Perhaps the most nasty situation is that : You have some signal between Module A and Module B. There's a fault on A, so that the timing of this signal gets out of spec. For some reason you replace B first, and the replacement is more tolerant of bad timing. The machine works again. But the timing continues to drift, and eventually the machine fails again. I have actually seen this one happen. Thing is, they may not end up in the machine they were originally used in (this is certainly the case round here, I've got half a dozen machines using that brick!) and thus you've changed more than you have to in that machine... What I'd do here is tweak it back to 15V (Assuming this is possible and that the preset is not hard against the stop) and then keep an eye on that voltage. If it starts getting low again, you know there's a problem.. Indeed. -tony