Ok, I was reformatting the hard drive on my Amiga 4000 when all of a sudden it stopped. The screen went dark grey and the hard drive LED goes on and off, on and off. It also sounds like the hard drive is running at different speeds. I tried hooking up different hard drives, same thing.
I am scratching my head on this one. 
yes might be the psu l got broken 4000 got wait till christmas 2011 to get looked at agghhhh
the main thing is not to panic it can be fixed
does it get a boot screen ie the disk logo
they also wont boot if your got cpu card thats unseated a bit . but with drive speeding up
does sound power realated , my psu spins but doesint power the hd at all .
l rushed puting back toghter and the floppy drive power plug arched and stoped the machine working.
am looking at getting plug converter to try atx pc supply and he hoping my machine work again.
good luck
