Mac Pro quits after trying to boot

[Hitcher]

Everytime I press the power button, the white power LED comes on for a few seconds, and I hear fan noise then the machine just "clicks" off, almost as if someone removed the power cord abruptly. Needless to say, I didn't remove the power nor was the supply interrupted. I've tried diagnosing the problem by removing external devices one by one, but that made no difference. Also I've tried all possible resets etc.

See my video for more details. Even paying for help at the local ASP didn't help me:

http://www.youtube.com/watch?v=uq2LHDMFmHw

Thank you for trying to help me out.

 

[macuserx86]

Try re-seating the RAM modules and the graphics card.

This has fixed similar problems with my Mac Pro (which is the same model as yours)

If that doesn't work, try re-setting the PRAM battery.

 

[Hitcher]

Re-seating the RAM-Modules and graphics card didn't do the trick.

I am going to try to re-set the PRAM battery.

 

[iamcheerful]

Everytime I press the power button, the white power LED comes on for a few seconds, and I hear fan noise then the machine just "clicks" off, almost as if someone removed the power cord abruptly. Needless to say, I didn't remove the power nor was the supply interrupted. I've tried diagnosing the problem by removing external devices one by one, but that made no difference. Also I've tried all possible resets etc.

See my video for more details. Even paying for help at the local ASP didn't help me:

http://www.youtube.com/watch?v=uq2LHDMFmHw

Thank you for trying to help me out.

Highly likely PSU at fault. I'm surprised that the local ASP didn't picked that up.

 

[Hellhammer]

http://guides.macrumors.com/Mac_doesn't_boot

 

[iamcheerful]

http://guides.macrumors.com/Mac_doesn't_boot

nice writeup. didn't look at the details yet, but definitely a great start!

Back on topic:
just watched the youtube video, saw the short scrolling feed, makes me more certain it is likely a PSU fault. did you buy ACPP? i noted that ACPP wasn't part of the invoice displayed. i'm wondering if you bought ACPP later (unlikely so as you had to pay 75 € ...

you stayed pretty cool to shoot a video clip even after having the machine "shipped away" for 3 weeks!

p.s. yep, i replied even before watching the video.[/size]

 

[666sheep]

Hitcher, try to start your mac without graphics card.
If it won't help, check diagnostic LEDs (you will find Mac Pro 2008 service source on Scribd).

@Hellhammer: nice guide , only one thing needs to be corrected: option is "alt" key, old  key is "cmd" or "command"

 

[Hellhammer]

nice writeup. didn't look at the details yet, but definitely a great start!

@Hellhammer: nice guide , only one thing needs to be corrected: option is "alt" key, old  key is "cmd" or "command"

Thanks guys! Should pretty much summarize all things you can do without taking your Mac apart.

BTW, fixed the alt/ key thing

If it's PSU issue, I wouldn't worry, new PSU is something like 100$ anyway, new logic board would be +1000$. Try the guide and we'll know more

 

[Transporteur]

SU issue, I wouldn't worry, new PSU is something like 100$ anyway, new logic board would be +1000$. Try the guide and we'll know more

100 bucks for a replacement Mac Pro PSU?
Where did you get that price?

A colleague of mine paid well over 300€ ($400) for getting a replacement in an Apple Store.
The spare part without service shouldn't be much less than hat.

 

[Hellhammer]

100 bucks for a replacement Mac Pro PSU?
Where did you get that price?

A colleague of mine paid well over 300€ ($400) for getting a replacement in an Apple Store.
The spare part without service shouldn't be much less than hat.

I meant PSU generally, does it have to be the Apple PSU or does any ATX PSU work? You can get 850W for 100€ in here

 

[Transporteur]

Of course it has to be the Apple PSU.

 

[nanofrog]

If it's PSU issue, I wouldn't worry, new PSU is something like 100$ anyway, new logic board would be +1000$. Try the guide and we'll know more

Last I checked, the PSU's go for nearly $300USD, and the boards for ~$800USD. Granted, those are US locations, but given how things tend to be priced in Europe, I wouldn't think they'd be less expensive.

 

[Hellhammer]

Last I checked, the PSU's go for nearly $300USD, and the boards for ~$800USD. Granted, those are US locations, but given how things tend to be priced in Europe, I wouldn't think they'd be less expensive.

I was under the assumption that you could use 3rd party PSUs too but looks like I was wrong.

Well, OP hasn't replied yet, maybe he got it to run

 

[nanofrog]

I was under the assumption that you could use 3rd party PSUs too but looks like I was wrong.

Well, OP hasn't replied yet, maybe he got it to run

The wiring is different.

But it should be possible if you had the ability to trace out every single wire, and adapt the original PSU's wire harness to a new PSU (standard PC version). But you'd really want a working MP PSU to facilitate this (use a meter instead of tracing out the PCB's). Either way, this takes time, and requires both special skills and tools (DMM).

 

[Hitcher]

Thank you very much for your replies. Yesterday I brought it to another ASP because it is to difficult for me to repair it myself. I've tried to take all the parts out of MP one by one but that doesn't help. I also did a clean install of OSX Snow Leopard.

The strange thing is that sometimes the system boots up and when that happens the MP keeps working great. With one successful boot you can keep on booting the machine up and there is no problem at all. It is until the next morning that the cycle starts again.

Of course I will post again when the ASP returns the MP. I hope for the best now because I bought no Apple care. The ASP told me that the PSU is the cheapest part. Replacement of the Logicboard is $ 600,00 and the CPU more then $ 1.000,00.

 

[macuserx86]

Thank you very much for your replies. Yesterday I brought it to another ASP because it is to difficult for me to repair it myself. I've tried to take all the parts out of MP one by one but that doesn't help. I also did a clean install of OSX Snow Leopard.

The strange thing is that sometimes the system boots up and when that happens the MP keeps working great. With one successful boot you can keep on booting the machine up and there is no problem at all. It is until the next morning that the cycle starts again.

Of course I will post again when the ASP returns the MP. I hope for the best now because I bought no Apple care. The ASP told me that the PSU is the cheapest part. Replacement of the Logicboard is $ 600,00 and the CPU more then $ 1.000,00.

What is the Mac Pro plugged into? Have you tried different wall socket/power strip combinations?

The fact that it boots up at all makes me skeptical that it's a bad PSU; usually when a PSU dies, it's dead for good. I could be wrong though.

 

[Hitcher]

The problem is solved!!! The ASP did a swap of the PSU between two machines. Now my machine was working all right and the other machine had the problem I described.

I had the same line of thinking regarding the PSU. How is it possible that it works occasionally. I don't know the answer to that but the fact is that the problem is solved now.

So the next ASP resolved the issue within a day. I am very happy with the result and hope that this post will help people dealing with the same issue.

Thank you all.

 

[iamcheerful]

A batch of Mac Pros had "sub-standard" PSU installed. I guess yours was one of the "lucky" ones. Pity Apple didn't offer a voluntary recall/exchange on these affected ones.

Still it is additional cost on your part. The next time (if you still do) get a Mac Pro, seriously consider ACPP.

p.s. as to why it works at times, well, look at it this way ... we humans can be sick, having headaches etc, but we still do function pretty well at times especially after sufficient rest. just a thought ...

 

[Hitcher]

I know for sure I will order the ACPP. The PSU is around € 300,00. Still it is much less then buying a new MP. I am also happy that is was not the logic board or the processor.

 

[iamcheerful]

i'm glad you've found a somewhat happy resolve. thanks for keeping us posted!

btw, you really stayed cool to shoot those 2 videos. are you going try to get a refund of your 75€ from the 1st ASP? they should make good given the kind of inconveniences and distress they put you through!

 

[nanofrog]

How is it possible that it works occasionally?

Thermal cycling on aged electrolytic capacitors can do this (there's usually physical evidence, such as either leaks of a thick, sort of oily green-brown substance on the PCB or bulging).

Be glad that's all it was, as there are times that when a PSU goes, it takes other items in the system with them, such as main boards, RAM, and processors.

 

[iamcheerful]

nanofrog, thanks for the proper term.
And yep, really lucky that the PSU didn't fatally damage the other electronics.