The
hp 5216A is nearly on the "it's dead Jim pile", turns out to have manufacturing defect, one of the wires going to the transformer primary was trapped underneath the transformer, eventually it had damaged the insulation & shorted out half of the transformer primary, i.e ended up with 230V across one of the 115V windings, resulting in the blown fuse & it getting sold for spares on evilbay.
I've removed the squashed wire & added heatsink sleeving. Unfortunately on testing with the DMM, I found one of the split 115V primary windings is open circuit.
And testing with a 110V step down transformer, it is still drawing to much current, I've run out of time to determine if the transformer has shorted turns, or the PSU has died again.
For anyone else with an early 5216A, here is the A6 (05216-6002) PSU diagram, as the one in the Agilent scanned manual is complete utter shite.
David