Unable to boot after an attempted installation of a 2nd GPU

[MarkDavid]

System:

PSU: Corsair PSU RM850e
Motherboard: MSI B550-A PRO

CPU: AMD Ryzen 7 5800X3D (w/ cooler - BE QUIET BK022 CPU cooler Dark Rock PRO 4)

GPU: GIGABYTE|NVIDIA GeForce RTX 3060 Ti

RAM: G.SKILL Ripjaws V DDR4 2x 16GB

https://pcpartpicker.com/list/gY8w28

 

Was using the PC today, it worked just fine. I decided, that I would like to test out potential GPU passthrough for a VM and installed a second GPU (Gigabyte GeForce GTX 1060 6GB) I had lying around. The installation went fine, I booted up into the system, logged in and then then I saw that the signal to the monitor was lost. Thinking that maybe the drivers had decided to output the signal via the second GPU, plugged in my monitors to it. But here I realized that something had happened and the computer no longer worked.

 

The first thing I identified - the Ez Debug CPU LED was LIT WHITE, which indicated a real problem here. Here is what I have done since then:

 

1. Revert back to the state where the PC worked (removed the 2nd GPU). Same issue.

2. Since the fans spun up, the MB got power, but maybe something went wrong with the PSU. Switched around the connectors, reseated them - white CPU LED.

3. Despite the fact that the MB seemed to get power, borrowed a PSU from my NAS computer (Corsair PSU RM750e), plugged in without GPU's - same issue, white CPU LED.

4. I assumed here, that the original PSU was fine, went on to do additional identification.

5. Removed all storage and RAM from the device. Expected for the LED to switch to DRAM, but it stayed on the CPU (actually, without GPU, it should have switched to VGA LED, as the CPU does not have integrated graphics).

6. Unplugged and reseated ALL cables from the PSU, fans, frontboard, audio and similar. Whatever I could find - same issue, white CPU LED.

7. Cleared out CMOS by removing it and waiting for 10 minutes.

8. Removed the cooler and the CPU, checked for any damage to the CPU, no damage present. Reseated the CPU, reapplied thermal paste, installed the cooler. Tested just with the CPU installed, no change, white CPU LED.

 

From the manual and general troubleshooting others had gone through indicates that the boot process fails somewhere very early and now I am out of my depth in trying to identify the issue. In this case, my assumption is that something happened during the installation of the 2nd GPU (or potentially too much power? but I feel like the PSU should have been able to handle an addition of this GPU) and borked either the motherboard itself, or the CPU.

 

Any suggestions here? I currently do not have the capability to test the CPU in another Motherboard, as I don't have one with a fitting socket. I would have done so if I had.

[BoomerDutch]

Uhh you can't enter bios at all?

 

Have you tried changing cables of monitor to GPU.

 

Is it not white led meaning debug mode?

[MarkDavid]

9 minutes ago, BoomerDutch said:

Uhh you can't enter bios at all?

 

Have you tried changing cables of monitor to GPU.

 

Is it not white led meaning debug mode?

Yes, I am unable (or at least, I believe I am unable, will double-check) to enter BIOS at all.

It seems that the MB gets power and nothing else happens afterwards.

 

The reason why I think that I am not reaching BIOS is that I have tried to boot up with both of the GPUs as well (installed standalone, not two GPUs at the same time) and had connected monitors. I have three monitors, and I have multiple HDMI and DP cables and I have tried a good combination of them. But will try to double-check this as well.

 

Would you be able to expand on what you mean by the debug mode? At least from the manual, I understand that the MB has four indicator LEDs that allow for easier debugging of potential issues. In this case, it fails somewhere very early (again, at least I assume that), as it does not show any other indicators at all, when in should (e.g. showing that there is an issue with RAM, if no RAM sticks are present).

[BoomerDutch]

2 minutes ago, MarkDavid said:

Would you be able to expand on what you mean by the debug mode? At least from the manual, I understand that the MB has four indicator LEDs that allow for easier debugging of potential issues. In this case, it fails somewhere very early (again, at least I assume that), as it does not show any other indicators at all, when in should (e.g. showing that there is an issue with RAM, if no RAM sticks are present).

Well I've gathered info from chatgpt and gotten 2 answers from it.

 

1. Its working fine
2. Its in debug mode (you have to exit it)

It told me you'll have to go into bios and disable debug mode.

 

If there was any issue indicator should be able to tell you what's wrong like cpu or ram or else.

 

So we'll need to confirm if it's motherboard or not, can you try remove everything including cpu and boot it and see if it's indicating that there's cpu issue or still white led showing 

 

That is if you read manual which color or flashing led is indicating cpu issue.

 

Strange behaviour if you ask me.

[OddOod]

Welcome to the forums!
Can you unplug and replug the CPU 4pin connectors at both ends? Maybe they got jostled while you were in there

[PDifolco]

It's a really improbable coincidence that the CPU died while you were installing your second GPU

What could have happened tho is that you've damaged or shorted something on the board while installing it... Can you have a good look at your board ?