[DMcMahon]

Found the > 70 volts drop across the 200mA HT fuse was due to very bad contact resistance on the copper (looks like copper) fuse holder contacts. There was Verdigris on the underside of the copper contacts and despite cleaning with crocus paper and contact cleaner I had a hell of a job obtaining consistent good contact resistance/volt drop free.

The other 2 fuse holders are not as bad but also suffer from poor contact resistance, but the AC voltage on these seems to cope better than the DC voltage on the 200mA fuse.

Ideally I would like to renew these poor fuse holders but due to their single side contacts, normal double sided fuse holders would be too deep/high for the available space plus would not really want to disturb the fuse/mains voltage selection panel again with the very tight connections behind including the very fine/delicate transformer wires.

So will press on with existing fuse holders to see how it goes. Currently have got good contact resistance/virtually zero volt drop across the 200mA fuse, but am not confident how long this will last.

Maybe the poor contact resistance is why the 500mA AC mains fuse had the silver foil around it.

Powered up again this time with the Output Module connected, first removing the ECL 82 Triode Pentode valve. Have not seen an ECL 82 for a long time and had almost forgotten about Triode Pentodes until the other day when I read Garry's comment in the "Disconnected Speaker" thread.

After powering up found there was zero DC voltage coming back from the Output Module to the chassis. Traced problem to a broken yellow wire at pin 2 of the 7 way connector, this connects the DC supply from the output side of the 360 ohm smoothing choke L3 in the Output Module to pin 2 for the DC HT supply for most of the electronics in the chassis (designated 260V B).

So will repair the broken wire and test again. There are 4 old Wima waxed paper capacitors in the Output Module that I will replace, but will first out of interest, will test for leakage/DC voltage passing with power on them.