Unhappy HP-85

OK, I've got out my HP85 service manual. The 3 transformers on the PSU/printer PCB are : T1 (Lower of the 2 large ones), converter transformer from +12V to +5V T2 (small onme), current sense transformer for +12V/-5V PSU T3 (Upper of the 2 large ones), +12V/-5V SMPSU transformer, +6V PSU the winding details for the transformers, here you are (pin 1 is the top left pin looking at the componet side of the PCB -- it has a square solder pad, pins then number conunterclockwise like an IC) (T = number of turns) : T1 : 2 windings pin 1 (start) -- 27T -- pin 2 -- 27T -- pin 3 pin 4 (start) -- 15T -- pin 5 -- 15T -- pin 6 T3 : 2 windings pin 6 (start) -- 20.5T -- pin 3 -- 5T -- pin 2 -- 17T -- pin 1 pin 5 (start) -- 15T -- pin 4 You would have to get the wire sixe by measuring the wire on the existing transformer, and you'll have to re-use the original cores. Those are C1 and C8. C1 is the smoothing cap for the incoming supply (26V AC, rectified on the PSU board), so if that shorts it'll take out the mains fuse at the back. C8 is the smoothing cap for the 12V line. While this could damage T3 if it shourted, I am suprised the PSU didn't shut down. I'd check the rest of those PSU components very carefully (you want to get the HP85 service manual, although you're not 'supposed' to do component level repeair it does contain schematics). They are HP custom. The only place you'll get them is from another HP85 (I know from experiece that the 9915 (HP85 in a metal case that could fit into a rack mount kit) and the HP86 have totally different PSU transformers. I assuem the 87 does too, but I've not worked on that yet (a project for the near future, actually). -tony