Amiga 4000d IDE problems

[Audun]

Hey folks, I have recently gotten hold of an Amiga 4000 which was functioning optimally a couple of months ago. It's a standard edition with a 030 cpu, 3.1 roms, mediator with full package (sb, tv tuner, network card, voodoo, cf adapter)  - so what happened was, all of a sudden the CF card stopped functioning in the machine (but works on others). And now whenever I connect an IDE device (any IDE device except floppy) to the controller, the powerled keeps flashing like it's guruing and won't boot at all. When I disconnect all the IDE stuff except the floppydrive, it boots fine from floppy (although very slow before it starts, but I hear that is normal on 4ks).

Here's what I tried:
I checked for corrosion on the mainboard, leaked battery acid etc, none found. I removed the mediator with no result. I tried switching cpu boards, adding a buddha IDE controller - still the same crap. I'm completely lost as to what the cause may be. The ram also seems to work perfectly when I boot with WB 3.1 floppies.

Does anyone have a clue what could be the source of the problem? Please, I would very much appreciate any input I could get!

[Audun]

Thank you, stopthegop, these are good suggestions. I have already considered this though, and I have isolated single IDE units with no success. Before that I had also eliminated jumper settings as the cause of any problems.

The issue itself occurred with no apparent change in hardware settings, it just seemed to happen at random. So I remain puzzled as to what the cause may be. Would you happen to have any other suggestions? I am very grateful for any input here.

[Audun]

Good ideas, there is no leakage from the capacitators - but I will have to wait to confirm the psu as I don't have any means of checking the output, nor a spare psu to work with :\ Good suggestion though, thank you.