Replacing MicroVAX II PSU With a Modern PSU

-----Original Message----- From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Mark Wickens Sent: 24 November 2015 23:52 To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Replacing MicroVAX II PSU With a Modern PSU I haven't looked into this at all and I suspect it's probably quite tricky indeed. I did look around a while back drew a blank. If you need another dead MV2 let me know, the one I collected is still sat in the garage. Regards, Mark. On 20 November 2015 at 00:00, Robert Jarratt <robert.jarratt at ntlworld.com> wrote: > While I look into what is wrong with my H7864, I'd like to use a > modern PSU to power my machine (actually an rtVAX 1000). > > > > I think I would need to deal with the following problems: > > > > 1. Finding the right connectors (ideally, I am sure I could rig up > something more temporary). > > 2. A way to power the fans, which I believe are 15V, perhaps they > would run on 12V as I wouldn't run the machine for long periods > anyway, or I could just use PC fans. > > 3. Emulate the DC OK and P OK signals, I suspect these would be > simple > +5V signals which could perhaps just come from the +5V of the PSU > +anyway > (unless there is a problem with that). > > 4. The most difficult bit, I suspect, would be the PSU LTC signal , > which I believe is some kind of clock. I don't know what the spec of > the signal is, but I will get a scope on a working one to see (NB > don't want to risk a working PSU on this machine in case it was a > problem with the machine itself that caused the first PSU to fail, I > don't mind sacrificing a modern PSU if need be). > > > > Has anyone done this before? > > > > Regards > > > > Rob > >