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MP 1,1-5,1 Quick Help needed – cMP 4.1 red CPU LED and not booting after SSD install

bdavid32

macrumors newbie
Original poster
Aug 31, 2020
14
1
Hello, I just got a 2009 cMP 4.1 single CPU with 5.1 firmware flash. I wanted to install a PCIe SSD (AXAGON PCIE-NVME M.2 PCEM2-NC + Samsung 970 EVO). When I pressed the power button, the vents and DVD drive started as usual, but after one or two seconds I could smell a bit of smoke. No boot screen, red CPU LED turned on on the daughterboard. I checked the AXAGON adapter, it was the source of the smoke and the chip shown in the attached image melted.

I removed it from the PCIe and now the MacPro doesn't boot anymore... the DVD makes the normal startup sounds, the fans are spinning (including GPU fan), but the CPU led stays red and there's no image on the display.

Diag LEDs on motherboard:
CPU A OVTMP: off
CPU B OVTMP: off
PSU PWROK: Green
5V STBY: Orange

SYS PG: off
EFI DONE: Green
GPU OK: Green

Trying to boot with no RAM installed makes no sound.

Any help much appreciated! Thanks a lot!
 

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MIKX

macrumors 68000
Dec 16, 2004
1,786
662
Aussie in Japan
Like this ?


( Power cord removed for 5 minutes first )
NVRAM_PRAM_ResetMac.jpg


( Read the small black print ! ) THREE CONSECUTIVE " Happy Mac" chimes
 

bdavid32

macrumors newbie
Original poster
Aug 31, 2020
14
1
Like this ?


( Power cord removed for 5 minutes first )
View attachment 950485

( Read the small black print ! ) THREE CONSECUTIVE " Happy Mac" chimes
Thanks a lot for your reply,
I have performed the SMC reset multiple times, by removing the power cord.
As for the NVRAM, there is no chime and no image on the display, so I don't know if the keyboard combination helps in any way, as the system does't seem to try to reboot afterwards, but I have tried it multiple times anyway, with no improvement.

Meanwhile I managed to test the SSD on another computer and thanks God, it works flawlessly.
 

KeesMacPro

macrumors 6502a
Nov 7, 2019
590
167
Trying to boot with no RAM installed makes no sound.

The MP will not boot at all without RAM installed.
I'd remove all PCIe cards , install 1 GPU, 1 HDD/SSD with a known working OS, install 1 RAM module, connect it to 1 known working monitor and test it.
 

bdavid32

macrumors newbie
Original poster
Aug 31, 2020
14
1
Got another fully functional MacPro 4.1 and I swapped some parts between them, with the following conclusions:

1. The GPU (HD4870) is damaged. When I installed it in the other, fully functional MacPro I got the following: normal boot, chime, but no image on the display.
2. I installed the other GPU, from the functional MacPro (GTX 680) in the damaged MacPro and got exactly the same results (no boot, no chime, red CPU LED and no image on the display, only the fans spinning and dvd drive sound)
3. I installed the CPU tray from the working MacPro in the damaged one and got the same results again: no boot, no chime, red CPU LED and no image on the display, the fans spinning – but this time all these lasted for about 3 seconds; after three seconds, it powers off completely (and it does this consistently, every time I try to power it on; if I swap back to the original cpu tray, fans and cpu LED remain on).

The MP will not boot at all without RAM installed.
I'd remove all PCIe cards , install 1 GPU, 1 HDD/SSD with a known working OS, install 1 RAM module, connect it to 1 known working monitor and test it.
Yes, all this was done with everything removed from PCIE cards, USB ports, known working monitor + multiple SMC resets in between the steps. The HDD swap would be the next step, and if it doesn't work this way, it's most probably what I fear most, the motherboard.

Thanks a lot everyone for the help so far :)
 

bdavid32

macrumors newbie
Original poster
Aug 31, 2020
14
1
Ok, just swapped the HDD and the power supply, still no results. Any advice on troubleshooting the specific parts of the motherboard that may cause the issue?

Thanks a lot again!
 

KeesMacPro

macrumors 6502a
Nov 7, 2019
590
167
AFAIK there's no technical info available for troubleshooting/repairing specific parts on the backplane ...
 

bdavid32

macrumors newbie
Original poster
Aug 31, 2020
14
1
Ok, so now after swapping the CPU tray from the working MacPro to the one that didn't work one more time, the MacPro that did work, with it's original tray gives me the same symptoms: red CPU LED and no boot, just fans spinning, exactly as the other one...

Edit: Tried SMC reset, no results, afterwards I took it out, cleaned the contacts and now this one works again.

So this makes me think the most probable place to look for problems is in the parts that deal with the connection between the backplane and the cpu tray (especially the ones that deal with PCIe to CPU).
 
Last edited:

bdavid32

macrumors newbie
Original poster
Aug 31, 2020
14
1
Take care of one thing: if the cpu is upgraded it needs 5.1 firmware on the Backplane- otherwise the 4.1 would not post.
Yes, I'll keep that in mind, thank you!
The CPU is a X5675, so it needs the new firmware, in case I will be replacing the backplane, but that's not a big deal since the tray from the other MacPro has the original dual CPUs, so I hope I'll be able to use that one when performing the update.

But before looking for a replacement backplane (might be pretty hard to find here in Romania), I'll take one more look at the PCIe X16 -> CPU route, I know the chances to find the problem and be able to replace the actual parts are quite low, but I'll give it a try anyway when I'll have the time.
 
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