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TECK

macrumors 65816
Original poster
Nov 18, 2011
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Hi all,

I was in the middle of installing a Sapphire 11265-05-20G Pulse RX 580 into my cMP 4,1 with 5,1 firmware running High Sierra, so I can upgrade to Mojave. Once I plugged the 2 mini connectors to power the card, the system could not boot anymore. Pressing the DIAG button only shows the amber 5v STBY LED lit, on backplane board. I also see the DSI510 CPU LED lit, on processor board.

I started with the usual steps, by removing all hardware components (disks, cards, etc.), including one CPU and all RAM. I also tested with a voltmeter the BR2032 battery, to make sure I get 3V output.

I tried re-seating the processors by switching them and putting B processor into A, first only A, cleaned the processor, tight it in cross, 2 turns at a time. Then added one memory bar. The DSI510 LED is still on, like the processor is not seen. I added after the B processor.

The irony is I don't have any paperclips in the house, to do a short on the power supply and see if I have 12V power. I really hope is the power supply, even if the 5v STBY LED is on when I press DIAG button. The LEDs for OVTMP CPUA and OVTMP CPUB briefly flash red when I connect/disconnect the power.

If I unplug the mac from power source for a while and plug it back, I can hear the hard drives spinning but nothing else runs, no fans etc. After that, if I try to turn OFF/ON the Mac, it will start spinning the disks briefly (less than 10 seconds) and shutdown.

I ordered one on eBay for $50. Any advice what could be the issue?
 
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Hi all,

I was in the middle of installing a Sapphire 11265-05-20G Pulse RX 580 into my cMP 4,1 with 5,1 firmware running High Sierra, so I can upgrade to Mojave. Once I plugged the 2 mini connectors to power the card, the system could not boot anymore. Pressing the DIAG button only shows the amber 5v STBY LED lit, on backplane board. I also see the DSI510 CPU LED lit, on processor board.

a couple of stupid questions . . .

1. Did you power down and remove the power cord before you started the RX 580 install ?

2. Only ONE GPU in the system ? ( AMD & NVidia don't play well together. )

3. What was the prior card ? If an NVIDIa card, did you remove the NVIDIa drivers ?

4. And of course the RX 580 power cable was : 2 x Mini 6pin to 1 x 8 pin ?

just checking . . . ;)
 
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I swapped the power supply, it is not the case, Mac still dead.

1. Yes
2. Yes, one GPU, the Sapphire
3. It was the stock 2009 GPU, GT120. When I plug it back and power the Mac, the card fan starts to spin a little, as well the disks, then the Mac shuts down. I did not know I have to remove the old card drivers, never saw that in any YouTube tutorials.
4. Yes, I bought two 2mini 6pins to 1 8pins cables to be safe. Same thing.

If I remove all components and leave the processor tray in, I see the DSI510 LED pulsating very fast and making a light crackling noise.

I removed literally everything, except the power supply, backplane board and processor tray. What worries me is that I don't see any fans spinning on the new GPU. This is a brand new card, purchased from Amazon.
 
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Check that the GPU is seated correctly. I'm sure I read that some other users didn't seat the GPU correctly, given that it's a little tighter than factory GPU.

What firmware are you running?

Not all power cables are made equal. Can you use a different set to see if that makes a difference?

Although I didn't quite have the symptoms you're experiencing here, I did fix start-up problems a couple of times (after upgrading CPUs and installing/swapping GPUs on a couple of my cMPs) by holding down the power button to force it into programming mode as if you're trying to upgrade the firmware. Miraculously it worked, even though it was a punt from nowhere and there's no logic to it.
 
I ordered a 2009 backplane card. I had a friend with the same Mac model and when I switch the processor trays, everything was okay. Do I have to remove one processor, in order to flush the firmware from 4,1 to 5,1?
 
I ordered a 2009 backplane card. I had a friend with the same Mac model and when I switch the processor trays, everything was okay. Do I have to remove one processor, in order to flush the firmware from 4,1 to 5,1?
MP4,1 BootROM don't support Westmere Xeons at all.

So, if your replacement. backplane still have a MP41.xxxx.B00 firmware and your tray currently have Westmere Xeons, you will need to remove the processors and install the original Nehalem Xeons and then upgrade the BootROM to MP5,1. After that, upgrade to the current MP5,1 firmware.
 
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I currently have installed dual X5690s 3.46Ghz. The new backplane board has the original 4,1 firmware. I will have put back the old processors I kept before the upgrade, thanks for the useful info. It is a pain to redo the seating twice but that is the cMP old school life. :)
 
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I currently have installed dual X5690s 3.46Ghz. The new backplane board has the original 4,1 firmware. I will have put back the old processors I kept before the upgrade, thanks for the useful info. It is a pain to redo the seating twice but that is the cMP old school life. :)


Hi,

I am wondering if you solved your issue at all. I am running into a very similar problem that happened today. I was stupidly adjusting something in my case by my new video card and worried I shorted something out. Yesterday I installed the sapphire rx580 into my 2010 custom mac pro and updated to os high sierra. Everything was working fine. At the moment when i went to adjust something earlier today the computer shut off.

When I turned it back on, the display didn't show and eventually the CPU fans kicked into overdrive at full power. When I shut it off I get a red light at ovtmp cpu a. When I press the adjacent white button it shows yellow for 5v stby which I believe shows the PSU is still okay?

I re-seated both cpus and even cleaned + swapped them, adding new thermal paste and making sure it made good contact. Did a lot of troubleshooting by removing various hardware as well. I noticed a little cable with a wire near the heatsink is not fully fastened to the logic board. But it seemed to be working properly even before. I haven't removed the fans over the cpus in years.

I'm hoping at worst I fried the backplane and nothing is wrong with the dual core logic board. Really kind of at a loss. Been searching all over and finding similar issues although very few instances have users noting the cpu fan issue. Any help would be greatly appreciated...attached two images.
 

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Could be Northbridge rivets have perished and let go. Did you inspect the Northbridge heatsink and rivets? I strongly recommend applyingnew thermal grease to the Northbridge whenever doing the same for the CPUs.
 
Could be Northbridge rivets have perished and let go. Did you inspect the Northbridge heatsink and rivets? I strongly recommend applyingnew thermal grease to the Northbridge whenever doing the same for the CPUs.

Thanks a lot for your reply. I looked at it and the rivets appear to be fine. However there's a little wire that is loose from the logic board. Is it a heat sensing wire? I will take the fans off again later today and post some photos. Hopefully that may help get some more help.
 
This is after the problem occurred, but when my buddy was helping yesterday he mentioned this was loose and when he tried to disconnect the cord it separated from the logic board. Is it the thermal sensor for the heatsink? Can it be adhered back to the logic board?

Obviously not good, but I had not even removed the CPU tray for ages until the issue with the red light happened.
 

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This is after the problem occurred, but when my buddy was helping yesterday he mentioned this was loose and when he tried to disconnect the cord it separated from the logic board. Is it the thermal sensor for the heatsink? Can it be adhered back to the logic board?

Obviously not good, but I had not even removed the CPU tray for ages until the issue with the red light happened.
You ripped the pads off the PCB, you will need a new processor tray. It's the temperature sensor for the northbridge.

Maybe some really advance technician could repair it, but will need several bodges if even possible.
 
You ripped the pads off the PCB, you will need a new processor tray. It's the temperature sensor for the northbridge.

Thanks. I'm still perplexed as to why the issue occurred prior to even removing the CPU try. Could a minor static charge or disturbance cause something like this to occur? My concern is that it will persist even if I purchase a new dual CPU tray and replace it. Really appreciate your help.
 
Thanks. I'm still perplexed as to why the issue occurred prior to even removing the CPU try. Could a minor static charge or disturbance cause something like this to occur? My concern is that it will persist even if I purchase a new dual CPU tray and replace it. Really appreciate your help.
Difficult to say, test your Mac with another tray before buying anything.
 
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Difficult to say, test your Mac with another tray before buying anything.
Thank you very much. Based on the specs of my computer do I need to make sure I purchase a flashed cpu tray in order for it to work?
 

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Thank you very much. Based on the specs of my computer do I need to make sure I purchase a flashed cpu tray in order for it to work?
Trays can't be flashed.

If you have a early-2009 Mac Pro, you buy a early-2009 CPU tray or backplane, if you have a mid-2010/mid-2012, you buy a mid-2010/mid-2012 CPU tray or backplane.

You can't mix early-2009 with mid-2010/mid-2012, this is valid for trays or backplanes
 
Trays can't be flashed.

If you have a early-2009, you buy a early-2009 tray, if you have a mid-2010/mid-2012, you buy a mid-2010/mid-2012 tray.

Good to hear, thanks. I noticed a number of listings for sale saying the board was flashed so I wasn't sure if it was the backplane or both of them. Hoping I can find a CPU tray to test first but at worst I'll have to order a new one and test it out. Do you think there's a possibility the backplane has an issue?

Naturally with the error it shows, the CPU fans kicking into full power the northbridge sensor indeed seems to be the primary issue. I will update when I figure out my next course of action. Appreciate your attentiveness.
 
Good to hear, thanks. I noticed a number of listings for sale saying the board was flashed so I wasn't sure if it was the backplane or both of them. Hoping I can find a CPU tray to test first but at worst I'll have to order a new one and test it out. Do you think there's a possibility the backplane has an issue?

Naturally with the error it shows, the CPU fans kicking into full power the northbridge sensor indeed seems to be the primary issue. I will update when I figure out my next course of action. Appreciate your attentiveness.
Could be, needs a diagnose. Without a functional tray, you can't diagnose it.
 
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