On Fri, Nov 27, 2015 at 1:09 PM, tony duell <a...@p850ug1.demon.co.uk> wrote:
> > There is a pdp 11 troubleshooting guide on Bitsavers that covers the h742 > > powersupply and regulators 744. 745, 754. Assuming that is what you > have. > > > > They're all tough to work on especially the regulators but I agree with > > Tony that you need to lock down the main suppl first. > > I am not sure what you mean by 'tough to work on'. If it's a physical > access > problem then what I did was to obtain a spare 8 pin mate-n-lock plug and > socket and make up a pin-pin wired extension lead about 1m long. Then I > can take the brick out of the PSU, connected it via the extension lead and > be > able to probe it. I normally sit it on top of the CPU box of my 11/45, you > get > easily enough air flow from the fans to run it for testing. > > If it's that the circuits are complicated, well, remember these are > swtiching > regulators (not linear) but are a lot more repairer-friendly than most > SMPSUs > in that nothing in the brick is directly connected to the mains. > > -tony > Tough-sh to physically work on/test. These are not made for field service IMHO, just swap out part. -- Bill
