What have I done.....

[doctorq]

Start by testing the motherboard. You can do so by connecting a floppy power connector of a PSU to the one on the Amiga motherboard. Connect the composite out of the Amiga motherboard to a TV card in a PC to get picture, or use the build in TV modulator to connect it to a TV if you have the cable.

Turn the power on, and let it be so for about 30-45 seconds. If you get picture the board works (at least boots) but if you don't get a picture it is most likely dead.

[doctorq]

@orange

I used it for over a year without damaging my motherboard (B1230, HDD and CD), so I see no problem by using this method as for testing purpose. In fact, I used it not more than two weeks ago for testing a Blizzard PPC 060/240/SCSI, and it was the only power source the computer got.

The -12V is used in order to not have a interupted sound. If -12V isn't connected there will be a noisy every x seconds. If -12V is supplied through a Mediator or G-Rex busboard for instance, the -12V connection isn't needed anymore, as the computer gets -12V through this.

In the end, if the original power connector is at hand, it would be the best to use this for every day usage. In a tower extra power can be supplied at the floppy power connector at the motherboard.