The PSUs in the Acorn BBC Micros are we'll know for blowing caps. Replacing caps is a standard thing when bring any BBC Micro back to life.
The StarDot forum is a good place to ask specifics about a Cambridge Workstation - http://www.stardot.org.uk/forums/ On 30 July 2017 at 17:28, Tony Duell via cctalk <cctalk@classiccmp.org> wrote: > On Sun, Jul 30, 2017 at 5:18 PM, Jules Richardson via cctalk > <cctalk@classiccmp.org> wrote: > > On 07/30/2017 10:59 AM, Ian Frost via cctalk wrote: > >> > >> Any body any experience in fixing these old Acorn PSUs - or managed to > >> source alternative modern supplies? > > In general smoke from a power supply that keeps on working is from the > mains filter capacitors. Some makes are well-known for this. I would > carefully examine them, they crack when they fail > > There will be class X capacitors between live and neutral and class Y > between > live and earth and neutral and earth, The former are the ones that > normally fail, > but I would change the lot. > > > Unfortunately I did trace out some, possibly all, of that PSU (most > likely, > > it was certainly a VMS-something in my ACW) years ago, but even if I do > > still have the schematics, they're on the other side of the Atlantic. The > > PSU in mine had the rectifier diode on the +12V rail go intermittent, > so it > > would start sometimes and not others. > > > > Tony D. might have schematics, but I have a feeling they weren't part of > the > > ACW service manual as the PSU was bought in from an external supplier and > > not an Acorn part. > > I certainly traced out the schematics of mine, but I forget which PSU was > fitted to my machine (something tells me it was made by Farnell). I can > try to find them. > > -tony > -- 4.4 > 5.4
