Thanks for all the replies over the last few days. I am sorry I have not replied to them, I have been away for work all week (and will be away again over the next few weeks). I thought I would gather up my various responses into one email, so here goes. To the person who asked about the enclosure. This is a BA23 and has only one PSU, so without that PSU I cannot try to get the machine running again. The harness I have is not the same as either of the two that someone sent me pictures of. It is not a ribbon cable, it has discrete wires, of different lengths, its part number is 70-20450-01, rev C1 and there is a date of 9th Dec 1985 on it. The actual connectors though look like the connectors on the bad ribbon cable harness, I think they are MTA-156. Some have suggested it blew because I had insufficient load. I had a TK50 and an RD53 attached, would that no be sufficient. Furthermore I did not actually switch the PSU on, just connected it to the mains, would the load connected to the PSU matter when the PSU is not actually switched on? There was also a suggestion that the PSU would have needed switching separately for 50Hz operation as well. The hardware manual I have for the machine tells me how to switch between 110 and 240, but does not say anything about switching it for frequency, so I suspect this was not an issue here. repair. Is there anyone on this list who is in the UK who would be willing and able to fix this PSU, or who knows someone who might be? Thanks Rob