Mac Pro early 2008 (3,1) will not boot - no video, no chime. Can it be saved?

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Mac Pro early 2008 (3,1) will not boot - no video, no chime. Can it be saved?

I have had my Mac Pro 2008 since new and it has run every day since then as Apple never made the Mac I wanted to replace it with. It started playing up a while ago in that if I shut it down and then booted it up again it would chime, go to the grey apple screen with the progress bar and then suddenly restart before completing the boot. This happened several times but once it booted correctly it was rock solid and I just left it on. If I did a "hot" restart it was also fine.

I went on holiday (and backed it all up beforehand) and shut the machine down (wondering if it would restart when I came back!). On my return it chimed on restart and but shut down as before. I just left it hoping it would sort itself out as before. It did not.

The symptoms now are as follows:

On starting it up there is no chime, I hear the relays click, the light on the power button light comes on and is solid, the fan on the stock Nvidia GPU spins up, the cooling fans spin up and the hard drives spin. There is no video output.

The red LED's on the RAM Cards flash on and off at power up.

The Diagnostic LED's on the mother board show LED 2 yellow for the stand by, LED 9 green for EFI loading complete. All the others are off, including (7) GPU detected and (8) All Power Rails Functional that should be on.

This makes me wonder if it's the power supply. I did check the power connector to the Nvidia card and measured 12v and 5v.

I have tried the following:

Removed and reset all the ram and risers. Removed all but two ram sticks.
Reset the SMC (and left the machine unplugged over night for good measure)
Removed and reset the Graphics card and replaced the PRAM battery (it was at 3.2V)
Pressed the reset button on the top RHS of the mother board
Removed all other cards (SSD expansion and USB 3 cards)
Removed all but one hard drive, and tried a couple of different ones that had systems on them
Used a hair dryer on the power supply to heat it up in case it was a bad solder joint that parted when it cooled

I get exactly the same results. It is obviously an old machine and I use it for legacy software and as my iTunes video server for the house, most of my work is done on a 2017 5K iMac.

Is there anything else I can try to narrow down the problem to GPU or Powersupply? I don't have any other Graphic card to try. A second hand power supply goes for around £70 and a replacement Graphics card is £60 here in the UK. My Mac Pro might just be telling me it really is time to buy that Mac Studio!

All suggestions are much appreciated.

Posted on Jul 25, 2022 7:31 AM

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Answer 1

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David White Author

Level 4

1,166 points

Aug 2, 2022 10:18 AM in response to Grant Bennet-Alder

Hi Grant, I wanted to update you on progress. I found a power supply but they are expensive in the UK and as the next step might be a mother board so it was all getting potentially more and more expensive. So I decided to jump ahead and buy a working 3,1 and found one for £90 ($110). I picked it up today and could swap things around. I confirmed that the original graphics card was in fact working fine as was the replacement 5770 I bought, so that is at least an upgrade. On a whim, I took the memory risers out of the new machine and put them in the old and low and behold it chimed and booted!

Investigating further I confirmed that all the memory sticks are in-fact fine but the problem was one of the riser boards, the one in A. If I just loaded up a couple of memory in the other (with only one card inserted) it would boot but the same configuration in the first would not. Swapping the good board between the two slots in the computer made no difference so it was the memory board. I have now ordered a new riser so with that hopefully I will have two working machines as the end of this.

We got there in the end, thanks for your help. The failure in the Memory Riser was not obvious as the power light did not show a failure and the red LED's on the memory board flashed as normal and the diagnostic LEDS on the mother board were misleading.

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Answer 2

Jul 25, 2022 8:17 AM in response to David White

Remove the graphics card, all other PCIe cards, ALL the drives including the DVD reader(s), and ALL the RAM.

When you power up, if the main processor runs, you will get a "help me" message -- a small integer number of blinks in the power-on indicator light. it is likely telling you "no RAM".

If you get that, power off, give it some RAM, and on next startup you should get a chime. if so, your Mac is working, but may have a bad graphics card.

Add back the graphics card and proceed from there.

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Answer 3

Jul 25, 2022 2:55 PM in response to David White

In some models, those LEDS only light when you press the Diag button

Fans come on? you have 12 volts and it's fine.

processor starts up? you have 3 volts and 5 Volts and its fine.

something happens when you press the power button (i.e., it attempts to start up)? you have standby power.

I don't think you have a power problem.

I think it is very likely your graphics card died.

DON'T replaces it with the same graphic card. Apple-firmware 5770 is a much better choice.

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Answer 4

David White Author

Level 4

1,166 points

Jul 27, 2022 5:47 AM in response to Grant Bennet-Alder

Hi Grant, I bought an Apple firmware 5770 which arrived today. I plugged installed it with everything else removed (drives, cards etc) and sadly I get the same result. No chime, no video, the Diagnostic LEDs do not show the graphics card attached or all the power rails, just trickle charge and EFI.

The fan spins slowly on the graphics card so it is alive but displays nothing on the monitor. I reset the SMC again just in case but I am now at a loss. What would you suggest next? Obviously there is a limit on what it is worth investing in a 14 year old computer!

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Answer 5

Jul 27, 2022 10:59 AM in response to David White

Take a look at this service guide:

https://tim.id.au/laptops/apple/macpro/macpro_early2008.pdf

Have you tried disconnecting the PRAM Battery? A bad or depleted battery can prevent a Mac from powering on or booting. The battery is not needed for powering on or booting the system as it is only needed to retain the PRAM settings like date & time, network settings, audio volume, etc.

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Answer 6

Jul 27, 2022 1:45 PM in response to David White

Used:

661-4677 Apple Power Supply 980W for Mac Pro Early 2008 614-0409 A1186 Refurbished -- $98.00

https://www.dvwarehouse.com/661-4677-apple-power-supply-980w-for-mac-pro-early-2008-614-0409-refurbished.html

be sure to check that this is the right one, I just picked what I thought to give you an idea.

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Answer 7

Jul 25, 2022 9:56 AM in response to Grant Bennet-Alder

Hi Grant, thanks for your suggestion. I did as you said and with no drives, cards or Optical drives and all the memory out, when I started the Mac the white light by the power button blinked continuously, I gave up counting.

I put the memory back and rebooted. There was no chime but the led by the power button was illuminated but not flashing.

Where do you think this is pointing?

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Answer 8

Jul 25, 2022 11:29 AM in response to David White1

I don't know what continuous blinking means. But is IS capable of blinking that indicator light, a strong indicator the main processor is running.

If you put the RAM back and NO blinks, it may be saying "I am fine".

No chime is disappointing, but not unheard of. it may be fine.

Next thing to try (on a speculative basis) is the graphics card. You should get an activated screen and a question mark.

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Answer 9

David White Author

Level 4

1,166 points

Jul 25, 2022 12:38 PM in response to Grant Bennet-Alder

Adding the graphics card leads to a start as described before, no chime and a blank screen - no signal. I tried a couple of different video cables to make sure it was not a faulty monitor connection and I tried another monitor.

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Answer 10

David White Author

Level 4

1,166 points

Jul 25, 2022 1:30 PM in response to Grant Bennet-Alder

It is the original Nvidia 880GT. I have had no problems with it. I am still concerned that the Diagnostic LED's don't show that all the power rails are functional. Could a graphics card failure do that? They show the same issue with no card present.

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Answer 11

David White Author

Level 4

1,166 points

Jul 25, 2022 3:52 PM in response to Grant Bennet-Alder

Thanks, I do only get the LED lights when I press the Diag button and the power ones don’t light up. It might be worth trying a different graphics card but I will have to buy one. A direct replacement is going to be as old a the one I have so I will have a look for a 5770 and let you know how I get on.

thanks for your help.

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Answer 12

David White Author

Level 4

1,166 points

Jul 27, 2022 12:55 PM in response to HWTech

Sadly removing the PRAM battery made no difference. I have the same service manual you kindly linked. I checked the diagnostic LED’s and the gpu is not detected and the power rails are not seen as being fully up (see my previous posts).

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Answer 13

Jul 25, 2022 12:42 PM in response to David White

what graphics card is this? the original cards shipped in the machine are long past their prime.

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Answer 14

David White Author

Level 4

1,166 points

Jul 27, 2022 12:47 PM in response to HWTech

Thanks for your suggestion. Yes, I replaced the PRAM battery as one of the first things I tried. I will try booting with no battery just in case the replacement is bad.

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Answer 15

Aug 2, 2022 10:43 AM in response to David White

Great progress and excellent troubleshooting!

Congratulations on succeeding through your Hard Work and thinking outside the box.

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Mac Pro early 2008 (3,1) will not boot - no video, no chime. Can it be saved?

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