MP 1,1-5,1 Mac Pro 5.1 Black screen freeze up after 5 min / Problem diagnostic ?

[AlexMaximus]

Hi

I have experienced this black screen since last week. At first it was kind of random. After a view days it happened every time, especially under Windows 10. So far, I checked the usual suspects. I thought it might be the GPU. Since I still have my AMD Radeon 580, I put that in and tested again. It took a little longer, but after a while the same result - Black screen. I also experimented with different Amd drivers on the Win10 side, - No luck. Because of this, I think it could be a degrading Power Supply. Maybe I have taxed it too much for too long With the occasional AAA game on Steam. I would like to know your take on this, if you have experienced a degrading Power supply or if it could be something else, like a melting CPU. I can get a new MP5.1 PS for a pretty penny, but I don’t want to throw money towards bad odds. What’s your experience on it? After all it’s a decade+ old computer.

 

[tsialex]

Get a cheap working MacPro5,1 to diagnose it. Buying parts piecemeal will cost you considerably more. If I was going to bet in anything being defective, is usually the CPU tray or the PSU.

CPU trays damage itself overtime when the MOSFETs thermal pads, the pink strip below the CPU heatsink, degrade and the oily residue becomes conductive with accumulated dirty. You should also check the push-pins of the northbridge heatsink.

 

[AlexMaximus]

Get a cheap working MacPro5,1 to diagnose it. Buying parts piecemeal will cost you considerably more. If I was going to bet in anything being defective, is usually the CPU tray or the PSU.

CPU trays damage itself overtime when the MOSFETs thermal pads, the pink strip below the CPU heatsink, degrade and the oily residue becomes conductive with accumulated dirty. You should also check the push-pins of the northbridge heatsink.

Thanks for advice. When I bought my dual tray upgrade two years ago, I did keep my single CPU tray with CPU. I exchanged it, but no luck. It took about 10 minutes, but got Black screen never the less again.
So GPU and CPU tray can be scratched off in terms of root cause. The PSU most likely is the culprit here since I did run the 5.1 heavily with Pixlas mod, high power GPU, tons of HDDs and all slots filled.
I am lucky though, somehow I found one brand new PSU at a store in original package for 275 bucks. I guess I shall go for that one?

 

[tsialex]

I am lucky though, somehow I found one brand new PSU at a store in original package for 275 bucks. I guess I shall go for that one?

I wouldn't buy it, no way. Even if it's really brand new/NIB, now the PSU is at least 11+ years old and unused capacitors age worse.

For this price you can get a working single CPU mid-2012 without much trouble searching. It will be a money much well spent, even more if the PSU is not the culprit, but the backplane or one other thing that you are not expecting, like a cable or the front panel board.

Btw, did you tested without any SATA drives? Tried to run AHT/ASD?