Question How do I interpret my ezdebug indicators?

[torchlyte]

I'm troubleshooting a failure to boot. My system has been working fine for months. I booted into Windows recently, shut down my computer, then turned it on again only to find it getting stuck in a cycle.

The cycle:
The ezdebug CPU LED flashes on and off while the PSU clicks.
The ezdebug DRAM LED flashes on and off.
The ezdebug VGA LED lights up and stays lit for a bit. It turns off when the next step occurs.
The ezdebug CPU flashes on and sort of "fades" off while the PSU makes another click.

The BIOS screen never shows up. The cycle repeats.

I've referenced the user manual for my mobo online, but the documentation on the ezdebug functionality is just one sentence per LED. To me, it seems like what's being indicated is a CPU problem, but I'm not entirely sure.

If it is a CPU problem, I suppose there are three solutions: get a new CPU, get a new PSU CPU cable, get a new mobo.

Some other things I've tried:
Disconnecting all the drives from the mobo and PSU.
Swapping my GPU for an older one I had on hand.
Using a different PSU with its own cables (but I'm not sure that the old one even works, it's been off and disconnected for a while). Nothing seemed to power on when I tried this.
Removing the CPU fan and CPU and putting it back in. Nothing seems to be bent or broken.
Disconnecting each RAM chip.

MOBO: MSI PRO B760M-P DDR4
PSU: Coolermaster V850
CPU: Intel i5-13400F, probably too much thermal paste but I don't think I had any heat issues
Typical GPU: RTX 3090
Current GPU: Some flavor of Gigabyte 1060
I alternated between Linux and Windows and frequently changed the boot order because GRUB wasn't handling it.

 

[Lutfij]

Welcome to the forums, newcomer!

CPU: Intel i5-13400F, probably too much thermal paste but I don't think I had any heat issues
You might want to pass on an image of how much thermal paste was added between the processor and the cooler. This would also be a good time to check for any bent or broken pins on the socket.

How are you cooling the processor again?

If the debug LED is stuck at a particular component, that is your culprit. If the LED is stuck at DRAM or CPU, then it could be the memory controller on your processor.

PSU: Coolermaster V850
Coolermaster have a number of V series units out there, which one do you have(if you're not sure, you can pass on a link to the unit)? If it's used, how old is the unit and what did it power prior to today?

Typical GPU: RTX 3090
You might want to source(borrow, not buy) a PSU that's reliably built with at least 1.2KW of power at the entire system's disposal.

The ezdebug VGA LED lights up and stays lit for a bit. It turns off when the next step occurs.
Would tell mem that the GPU is at fault here.

 

[torchlyte]

Thanks for the welcome and the response.

You might want to pass on an image of how much thermal paste was added between the processor and the cooler.
I've already cleaned it off, but basically the whole surface was covered in paste. I monitored the CPU heat back when I first built the machine. Originally it was running hot because I couldn't seat the stock fan properly. I bought an aftermarket heat sink and fan and the temperatures went down dramatically. This is what leads me to believe that "too much paste" wasn't really an issue, I just mentioned it for completeness.

How are you cooling the processor again?
I have a DeepCool AK400.

If the debug LED is stuck at a particular component, that is your culprit.
...
Would tell [me] that the GPU is at fault here.
I guess the confusing part for me is that the last light on is the CPU one, although it is true that the VGA light stays lit for a bit. It would not be terribly surprising to me if the GPU or its mobo socket were the issue, as those see heavy use in general. The most recent boot did not involve any heavy load on the GPU, however. I just used the internet and copied some files to a thumb drive.

Coolermaster have a number of V series units out there, which one do you have
Let's see... MPY-8501-SFHAGV
80 plus gold
850W
I suppose that may be considered insufficient for a 3090, so maybe that would contribute to an issue? Though it has worked fine for months and stably through heavy AI use. Also as I said, I swapped to a 1060 and still have the same apparent issue.
The PSU was bought new and I used PCPartpicker to help inform the decision.

You might want to source(borrow, not buy) a PSU that's reliably built with at least 1.2KW of power at the entire system's disposal.
I will have one available sometime tomorrow.

 

[torchlyte]

Some additional notes:
The GPU fan spins so it seems to power on as one would expect.
If I remove a memory stick, a message will display upon powering up that my "CPU or memory has changed" and that I should hit f1 or f2 to enter setup. Shortly afterward, the cpu led lights up and the PSU clicks off. Since the message being displayed on the monitor comes from a signal from the GPU, this tells me that the GPU does function to some degree.

 

[torchlyte]

I've obtained a 1200w PSU (RM1200x shift 80 gold plus etc.) and received the same result. I've also swapped between the 1060 and 3090 with the same result. To me, this indicates a motherboard problem related to the GPU. Right?

 

[torchlyte]

Replacing the motherboard seems to have done the trick.