Has my A3000 died?

[rkauer]

 Also check if one of those pins in the power connector had not coming loose from the motherboard (cold joint).

[rkauer]

 Change Paula and CIA...

[rkauer]

 Again: change CIA and Paula.

 You can swap 'em from any other from A1000 to A3000 versions! The CIAs are different only in A600/1200/4000/CD32 (SMD versions).

 And you can buy replacements from Amigakit or Vesalia. They have the chips in stock.

[rkauer]

Gwion wrote:
Oh I just remembered when I plug the +12V into the Amiga 3000's mobo it doesn't power, Any reason why this might be happening? I think its might controller the disk drive stuff?

 Not exactly. The 12V line is used only in the audio circuit and to feed the termination rail for SCSI devices.

[rkauer]

 Replace Paula.

 Check the electrolytic capacitors (swap 'em). Also look for burned traces, bad fuses and, specially, bad SCSI cables (nothing to do with audio business, but the problem can be on it).

[rkauer]

 So buy a spare A500 mobo for take the spare CIAs, Paula, etc..

[rkauer]

 The audio circuit needs +12 and -12V to work.

 Reliable operation is in 10.5~12.1V range (symmetric to the negative line).

 Distortion in audio indicate bad audio decoupling capacitors. Namely C433 and C443 in big-box Amigas. 22uF x 16V. Prefer swap 'em for no-polarized version. Using regular, polarized versions is a project error in the Amiga boards!

 Also Paula can be involved in the audio problem, since she is the responsible for sound generation (among other things).

[rkauer]

 BAD PSU!!! Check it before anything else!

 BTW: your CIA have gone south, a this time.

 Don`t trust on what you read from a multimeter with the PSU out of the board (no charge). Prefer to swap it for a newer unit, like an AT/ATX one converted (you need to swap the JP350 jumper position to use a PSU without the "tick" signal).