Mac Pro 2009 won't boot.

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Level 1

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Mac Pro 2009 won't boot.

Hello,

Since yesterday my computer simply refuse to boot (Mac Pro 2009, Quad-Core 2.93 with a flashed Radeon 5870).

It was working fine the day before, I shut it down, unpluged it and when I came back the following day it wasn't working anymore.

When I try to boot it I can hear the fans but not the starting "DONG" it should do.

I tried to replace the graphic card with my old ATI 4870, tried to switch with some old RAM I had and tried to disconnect my hard drives one by one but it did nothing at all.

The only thing I have is this red dignostical LED you can see on this picture. I tried to find it's meaning but I wasn't able to find anything.

It would be nice if someone was able to tell me what this LED meant (and even nicer if it wasn't something expensive to replace !).

Thanks !

Mac Pro 2.93 GHz Quad-Core, Mac OS X (10.6.8), 6 Go RAM, Radeon 5870

Posted on Jul 28, 2011 9:11 AM

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Answer 1

X423424X

Level 6

14,265 points

Jul 28, 2011 1:46 PM in response to lgda

I think (not 100% sure) that may be a processor diagnostic led. Not sure what it may mean though. Possibly over temp but hard to believe that if it's at boot time when things are still cool.

That picture might be more helpful if you could get closer to the led and cleared more of the dust on and around it.

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Answer 2

lgda Author

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Jul 28, 2011 2:40 PM in response to X423424X

Thanks for tying to help !

I tried to make a "clearer" picture, it's really dark but I think you can see the DEL (white thing in the middle) pretty well. Tell me if that's not enough (I'm not sure of what you need to see on the picture), I might be able to do better tomorrow with a better lighting.

I read somthing about this LED being an overheat indicator for the CPU but I'm not sure how I can use this information in my situation.

Thanks once more, I really appreciate it.

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Answer 3

X423424X

Level 6

14,265 points

Jul 28, 2011 3:09 PM in response to lgda

This 2nd pict is more clear.

"DEL (white thing in the middle)" ?? The thing I am looking at near the middle is just to the diagonally left o of the marking "D51510" and I indeed think that is the processor/cpu "A" diagnostic led. It may not only indicated over temp. It may also indicate that it thinks the processor is missing (dead?).

I'm basing this on what I am reading in a early 2009 Mac Pro service manual I happen to have. The manual goes on to say to check the heatsink of the processor, check for adequate thermal grease, verify fan is running, and to swap the processors to see if the processor is really failed.

This is a service manual not assuming and end user would be doing these steps unless you know how 😉

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Answer 4

ryan42

Level 3

859 points

Jul 28, 2011 7:35 PM in response to lgda

Hello, and welcome to Apple Support Communities!

You mention that you unplugged your Mac Pro. Do you do this often?

I am bringing some 1990's Mac knowledge in that may be largely irrelevant today, but old Macs would not boot if the PRAM battery was dead. The PRAM battery keeps the clock running and a few settings intact when the power is disconneceted.

It may be worth picking up a new PRAM battery (It's a 1/2AA 3.6V if I recall correctly) and seeing if that sovles your problem.

Also, check this Apple Technote for resetting the SMC and try that: http://support.apple.com/kb/ht3964

Regards,

Ryan

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Answer 5

lgda Author

Level 1

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Jul 29, 2011 7:25 AM in response to ryan42

Hello,

I do unplug my computer every day but use it every day too. I'll try to change this battery but can it explain the red LED ?

I did reset the SMC (and it did nothing) but I was wondering, do the SMC reset every time you unplug your computer for more than 15 seconds ?

I won't try to take apart my CPU because I'm not really familiar with this kind of manipulation but thanks for all the information !

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Answer 6

lgda Author

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Jul 29, 2011 7:56 AM in response to lgda

Just tried with a new battery but nothing changed, thanks for tying to help !

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Answer 7

The hatter

Level 9

60,990 points

Jul 29, 2011 8:15 AM in response to lgda

My G4 MDD is almost 8 yrs, same pam battery, even though not connected to power outlet or anything for months and has gone a year w/o being used once.

My Mac Pro is 5 yrs next month, I turn off the UPS as well every night.

PRAM batteries seem to stay charged and healthy without the need to replace.

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Answer 8

Jul 29, 2011 6:44 PM in response to lgda

Igda, I have a Mac Pro 8-Core with an ATI Radeon X1900 XT Graphics card, and I encountered the same problem almost a year ago.

The solution was simple: I removed the graphics card, and using compressed air, blew away the dust clogging the card's heat sink.
If you do this, be sure you jam any fans with a paperclip etc., so as not to generate electricity by spinning the fan.
I would also suggest checking the other heat sinks in the computer, including your processors' heat sinks, as when I did this I found that my mac was full of dust.

Let us know how you get on.

Steven

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Answer 9

lgda Author

Level 1

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Jul 30, 2011 1:00 AM in response to AceOnewheeler

Hello,

I bought a dry air spray, cleaned everything I could but it doesn't make any difference. The LED is still red and the computer still not booting.

You had the same red LED shining and it was caused by dust on the graphics card ?

Thanks !

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Answer 10

lgda Author

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Aug 1, 2011 9:46 AM in response to lgda

Hello once again,

So, I finally had time to look a little deeper into this processor board and after removing the heatsink and cleaning the processor I noticed two little plastic screws (the ugly little red arrow on the picture I took from macbidouille.com, not the nice and big one) maintaining another heatsink on the board.

I'm not sure what is the component under this heatsink but one of these screws was broken (they aren't really screws but I don't know how to explain in English) and the heatsink wasn't correctly positioned anymore so I replaced these two screws, put everything back in order (with some thermal grease on the processor and the unknown component) and everything worked like a charm when I was done.

Thanks everyone for your help !

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Answer 11

Mar 14, 2013 10:02 AM in response to lgda

Hi Igda,

I have exactly the same problem.

Can you tell me where did you find a replacement screw?

I want to have everything before unmount this.

Thanks in advance!!

Fred

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Answer 12

lgda Author

Level 1

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Mar 14, 2013 11:10 AM in response to Prophet_rs

Hello,

I don't know the exact model I used, I actually went to a local electronic store and showed the screw to get a similar one.

I don't think you have to find the exact same one (I didn't).

Sorry I can't be more helpful, I'm not really an expert in screws 😐

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Answer 13

Mar 14, 2013 11:38 PM in response to lgda

Thanks you a lot, it's the answer I needed!

Let's go to work then!

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Answer 14

Mar 15, 2013 8:19 AM in response to lgda

Done!

It's alive!!!

I used a inox screw and nut.

Thanks again!

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Answer 15

Xmorph

Level 1

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Mar 22, 2014 11:38 AM in response to lgda

Hi Igda,

I know your original post is quite old now but I'm hoping you can help me. It seems that I've got exactly the same problem as what you had with the red LED on the motherboard. I've also taken the main heatsink off and noticed that one of these little plastic screws/pins was broken. Can I ask where you got a replacement screw from?

Quite funny as Apple wanted to charge me £700 for a new CPU but I'm suspecting that this plastic screw is the cause of the problem on my Mac also.

Thanks,
Richard

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