It hasn't been out of use for such a long time, 1 year max. It gave up the ghost and the owner didn't want to start looking for a new power supply, so he gave the entire thing to Ebay.
When I opened the case i found that yellow crud everywhere. it's mostly seeping out beneath some of the big capacitors, but some of it also got elsewhere, for example on 2 big copper coils (it even connected them) and on some kind of cooler. On this cooler it burnt and smoked. After we removed some of the most obvious "connections" we got the inconsistent voltage. There'S none of it near the transformer or near the ventilation openings. It seems there's no dead short, the internal primary fuse doesn't blow. I'd have put in a PC power supply, but the Amiga needs a special 50/60 Hz(?) Tick signal.
Yes I collect old computers. I got old Macs, 2 Ataris, a C64, C128, Amiga 500 and PCs from XT up.
Did you know that Amigas are sold again? Amiga G3/800 MHz mainboard is 800 Euro.