2 beeps, loud fan, no video - Power G5.

I've spent days researching this problem on another computer and can't figure it out at all. Seems like the fan problem is typical with the Late 2005 models. The 2 beeps seem to indicate a RAM problem, but I have no idea why. Unfortunately, I am getting no video output so I can't run any diagnosis.

So far, I've
- cleaned the fans with an air compressor,
- tried turning on the computer both with and without the air deflector,
- reset the SMU,
- reset the PRAM,
- checked for insecure cables and cords

I don't know what else to do. I need this for work! Help. What else can I do?

Thanks!