8-Core will not boot - Graphic card runs loud and oscolates (cycles)
I have a 2007 8-core MAC PRO. About two years ago, I got rid of the stock GPU and purchased an ATI Radeon HD4890 for it.
All was working well until the other night all of the sudden the fan became very loud and started oscolating (cycling) between loud and less loud. About every second was the pattern of sound.
The system will not boot now. No beeps, errors, etc. The only thing I see is that there are two small LED's for CPUA and CPUB that are on, along with a label by them that says "overtemp". Those are on. If I hit the little reset button by them, I can turn the led's off.
In diagnosing, I purshased another ATI 5770 single card slot and put that in. Still won't boot up. I can also hear a very faint ossolating sound with this card too, but it's definitely not as noticeable.
I've pulled out the card and ram and tried running it. No beeps, etc.
I'm thinking that it might be a bad PSU, but hate to buy one on speculation. Any other thoughts?
Is this a good question?