IDE controller missing or corrupt?

You may be on the correct course. Have you any way of checking the fuse that seems to make no difference -- sometimes if a fuse has blown it looks like it's smoked inside. You could test it with small battery and a low voltage bulb or find a friend who owns a multimeter -- or find an electronics hobby store and take the fuse in and ask for a replacement. I may be wrong about the DC part and remember that my receiver is not quite the same model as yours. If the fuse that doesn't seem to make a difference is really 250 volts it isn't DC. If both fuses have identical lettering on the actual fuse body they may both be 250 volts as your observation suggests -- so you might try swapping them and see what happens. You MUST remove the receiver's power lead from the wall socket before touching anything marked 250 volts (that incidentally is the maximum rating of the fuse -- in Europe the power is 220 or 230 volts and in the US 110). Incidentally, there are other ways to diagnose faults on a receiver. Have you tried plugging a pair of headphones in to the headphone socket and see if there's any audio. If you can hook up another amplified system (say the speakers that come with a desktop computer) to the tape output of the receiver this may help narrow down the type of problem.