Quick story. Acquired the JCM2000 TSL122 after it was in storage for 11years.(a friends back bedroom). Tested it for about 3 hours, seemed fine, no crackles or scratchy pots or switches. The last Marshall service was in 2008. Tested again following day for about 2 hours same result, all good. Speakers wired as 16ohms into 16ohm socket. Another friend heard it running and asked to try it out at rehearsal with a view to buy it. At rehearsal it faded off a couple of times then died with a burning smell. He returned it, next day, dead as a dodo. First thing I noticed was the speaker jack was in one of the other 8/4ohm sockets and the impedance switch was on 4ohms. Probably, in panic to get it working, every socket and switch combination was tried. Yes the HT fuse was blown, a replacement slow blow T1A was also blown. Stripped the amp down looking for internal damage. (caps all discharged first). Here's what I found. So why was this 22J 6kV tantalum cap stuck on pins 3&4 ? Looking a the tracks it should have been on C46. Further examination of this board showed some minor damage to C12 and signs of a leaky C19 and that's all that's visible. So can anyone extrapolate what went wrong and give some pointers to a repair strategy ?