PSU failure in Mac Pro

[enafuit]

While working on my Mac Pro Xeon (2009) using Pro Tools Hd2 the Mac suddenly died.
After some investigation and advice I came to the conclusion that it was the PSU. So I replaced it and it worked for about 2 hours and then died.
Could there be something going on thats causing the PSUs to fail?
e.g. Jammed or clogged fan or dodgy card.

 

[iggibar]

While working on my Mac Pro Xeon (2009) using Pro Tools Hd2 the Mac suddenly died.
After some investigation and advice I came to the conclusion that it was the PSU. So I replaced it and it worked for about 2 hours and then died.
Could there be something going on thats causing the PSUs to fail?
e.g. Jammed or clogged fan or dodgy card.

Don't think a clogged fan(unless from the PSU itself) from the tower could cause the PSU to fail. Did you check all the wiring? Did you clean everything inside? You never know what might have gone in and possibly caused a short. How many devices do you have connected to your Mac? Are you 100% sure that your 2nd PSU was the correct version for your Mac Pro?
If the second PSU is clean on the inside, then something is either drawing too much power, or there is a short somewhere.

One thing that I noticed about these power supplies is that they LOVE to fill themselves up with dust! The first one could have died of natural problems, and the second one could have died due to overheating from too much dust build up. The PSU on my 2nd G5 died 2 weeks ago, and could NOT believe how much dust was in there. I don't think air could even move through from front to back properly. This made me take apart the PSU on my 1st G5, but it wasn't the same...looked like new. I added new fan guards and screen to the front of the fans so that I wouldn't have to take the whole thing apart again for cleaning in the future.

 

[enafuit]

Usually I have 1 or 2 external hard drives connected, 2 monitors two USBs and 2 iLoks. Yes the model numbers of the PSU were identical. Ive had the Mac Pro just over 3 years.But you would think that a short would Trip the fuse rather than kill the PSU. Ive never cleaned it, so I will now. Im going to have to get another PSU and hope for the best.
Many thanks for your reply.

 

[chscag]

You might also consider purchasing a line leveling UPS. With an expensive machine such as a Mac Pro I would never consider running it raw from the line. A good UPS is a must. I'm not saying that power glitches is what caused the second or even the first PS to die, however, why take a chance?

 

[enafuit]

After trawling the web for weeks I came across this.
Although my problem isn't solved as my Mac Pro is away being repaired. So I don't know if this will solve my problem but it is very interesting.

No Power on Mac Pro - Mac Pro - iFixit

"Do not replace the power supply unless you have the original system installation disks as they contain a program for syncing the fans. If the sync is not done the fans will run wild. "

This could be the reason for my 3 PSU failures.
I'm very surprised that this has not been flagged as a major issue by Apple or the sellers of Mac Pro PSU's (which there are quite a few).