Nightmare! My A4000 won't start any more! :((

[x56h34]

What CPU board are you using?
Try fitting a different one and see what happens.
Remove EVERYTHING from the system but 2MB of chip ram and (preferably) the stock CPU board, and see if you can boot. For the 030 C= CPU board, set the clock jumpers to INT and if you have an A3640, then EXT.

[x56h34]

I can send you my working 030 cpu board, if you wanna try and test your system. I suspect that your CPU board is busted, most likely.

[x56h34]

I bet that the A3640 card is busted.
Afterwards, I would suspect the ram simms, yes. :-)