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2008 Mac Pro random shut down help!

violst

violst

macrumors 6502
Original poster
Jun 14, 2012
339
161
Today for the first time my 2008 Mac Pro has randomly shut down twice, it also takes a few times of restarting before it will start up again. Any suggestions or experience with this type of situation will be greatly appreciated.

Do you think it could be the PSU?

Thanks.
 
try cleaning your videocard's fan with compressed air.
everytime ive experienced random shutdowns with my 3,1, this fixed it every time.
 
Thanks for the suggestion Wafl iron. I just swapped the 5770 that I have in their for an 8800gt but it still randomly shut down. Now that we seemed to have narrowed down that its not the GPU does anyone else have any suggestions?

Thanks

Is there anyway to test the PSU to see if its having any problems?
 
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Might be the Power Supply though not sure. In the office where I used to work, we had a Mac Pro that manifested intermittent shutting down and after examination by the Mac tech guy, it was the power supply. Try having it checked by a Mac technician.
 
Just had the same problem with mine, randomly turning off, especially when from a cold start. Looks like this is very common with mac pros... Do you get a relay "click" from the power supply and an instant shutdown? If so the power supply is most likely and something is causing the circuit breaker to trip. When I took the PSU apart the solder joints were shockingly poor, brittle and cracked, it should never have left the Delta factory like it, amazing it lasted as long as it did. I ended up re-flowing 90% of the solder on the top circuit board - DO NOT attempt repairing the psu unless you know what you are doing!

Try the following:

The manual - http://www.scribd.com/doc/17539946/Mac-Pro-Early-2008
iStat is good for keeping a check on how many amps the psu is able to supply or if anything is overheating
Check for kernel panics
De-dust and re-seat any video/pci cards & ram
Reset the SMC
Boot from a spare drive etc if you can - my HD got ruined, disk utility said it was toast, Disk Warrior fixed it :D
Check the power connectors etc on the logic board are seated ok
Check the error codes on the logic board between the ram risers - a pencil reaches in there nicely - all in the manual above. Even if the psu lights are green and the trickle power is amber (for ok) it doesn't mean the psu is ok...
Start the mac from cold - a cool environment will show up any bad solder joints easier. If it trips out try warming up the psu with a hairdryer, aim it through the holes at the top back and only at the psu - nicely warm it up don't cook it. Try it again, if it boots up bad solder is likely in the psu. Then it's time to get the psu looked at and fixed (check the electrolytic capacitors etc too), or shell out for a way over priced replacement :eek:
Good luck & hope this helps
 
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Thanks guys for the additional responses they are greatly appreciated.

Just a little more insight into the problem. A few months ago the system started to take a very long time to sleep sometimes it would take over a minute to sleep before that It would go into sleep mode immediately, It would also take about half that time for it to come out of sleep and for my tablet and keyboard to start functioning again.

I don't know if that is related to this problem. At this moment I am on the mac pro now but I don't know how long this will last before it shuts its self off again?

Also attached is a temperature log. The mac has been running for about 10 minutes. If someone could look at this and see if there is some temp that looks out of place.

Thanks.
 

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I think they look ok, I'm used to degrees C so someone else might notice something. Have a look at http://support.apple.com/kb/ht1237 and check you've got the latest firmware. Back everything up while you can!

I hadn't realized with my mac pro how it had gradually got slower, since fixing the psu it's a lot faster and boots up like it did when I first got it.

When it turns itself off is it like the mains plug being pulled (very fast) with a click sound?
 
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Hey Joshtin,

What you said is exactly what my mac does. Its like the power was shut off all of a sudden. When it shuts down it is in an instance, it doesn't do a slow shut down. And yes it makes a click sound.

Thanks
 
Ok so I was able to work on the computer for about 2.5 hours before it spontaneously shut off? I checked the LED's and they all showed up fine.

number 2 was amber and 7,8 and 9 were green.

Also my SMC firmware is upto date.

Any other suggestions?? I would love to fix this old beast.

Could it be a thermal problem?? causing the system to just shut off with no warning?
 
The leds are fine, if you've checked the video card and the ram/ram risers are all seated ok etc, so they are not tripping the power supply, it looks like it's the power supply itself. It sounds identical to my 2008 mac pro which was caused by bad soldering at the factory in the PSU, which would be an easy job for a service engineer to fix (also get them to check the electrolytic capacitors while they're in there) - or get another power supply. The instructions in the manual are good and it's pretty easy to remove/replace.
 
violst said:
Ok so I was able to work on the computer for about 2.5 hours before it spontaneously shut off? I checked the LED's and they all showed up fine.

number 2 was amber and 7,8 and 9 were green.

Also my SMC firmware is upto date.

Any other suggestions?? I would love to fix this old beast.

Could it be a thermal problem?? causing the system to just shut off with no warning?
Click to expand...

Seems to me people already answered you question a few times, it's the power supply, it's actually a fairly easy job if you can solder.

To the above Poster-Jooshtin, we hear about baking Logic boards all the time, now, would this maybe a good idea to try this out?
 
Thanks again Jooshtin, Your assistance and knowledge into this situation has been invaluable I greatly appreciate it.

I will keep you posted with any updates.
 
FYI, it appears to have been a bad ram chip. I removed a pair of ram chips from the bottom riser card and reset the p-ram the mac has been running stable for the last day and a half.

fingers crossed that was the problem. I had a problem with the bottom riser card about a year ago, so the riser may be on its last leg. But I would rather replace a riser card then a PSU.

Thanks again for the input.
 
That's great news violst :)

Justperry - only bake your psu boards if you like oven cleaning and have a replacement psu! :D
 
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