Weird A4000T startup problems

[nishtek]

Could be anything.  A4000T :
- get a AT power supply that you have tested
- get another cpu card and compare
- memory sticks should be tested on a PC machine and then used (a good reason to keep those old Pentium 2 mainboards with simms/edos)
- the scsi/audio connector properly seated
- roms properly seated.
- all other cards removed until you determine the issue.
if all else, then you can suspect ICs and / or capacitors.
thats our humble advice.

[nishtek]

> Not sure about the PSU how it could be damaged in such a way so that it would give these kind of symptoms. Ive had this machine jammed with hardware like CSPPC, Mediator, Voodoo, P-IV etc. How can I know if the PSU has been damaged?

Simple: measure the voltages of P/S, while power supply disconnected from amiga 4000.  note P8/P9 where they go etc.    a drop off in voltages could be the cause.  Mediator board could be failing.  I'd say Amiga technologies A4000T is pretty solid build boards so I doubt that this would go bad.  take all cards out and then boot only the amiga 4000T to OS 3.1 or something.  or boot from floppy drive.
it can be anything or any cards in the case that actually failed whcih is why I suggest you take it all out and boot only with motherboard - as with any PC motherboard troubleshooting.  if there was a sh***d of dust then you might know the answer to it as well.