CPU EZ Debug light won't come off and pc would not boot.

[Ijaaz]

A friend built my pc over a year now and it was working fine up until yesterday. I went to power it on and it lit up but the CPU EZ debug light is solid white and it would not boot. The monitor says no signal. I tried resitting the cpu, checking for loose cables, resitting the ram, almost everything I could think of but nothing worked so far.

Pc specs:
CPU- Ryzen 5 5500
Motherboard- MSI A520M PRO VH
RAM - 2x8GB Adata XPG Spectrix D60 3200Mhz
PSU - Azza 650w
GPU - ASUS ROG STRIX GTX 1660 SUPER

[phillpower2]

PSU - Azza 650w

AZZA do not make good PSUs, what is the exact model name or number of yours.

The following checks require the computer case to be opened so take the following safety precautions 1st, disconnect the power cord from the wall socket, press the case power button for twenty seconds or so to get rid of any residual charge in the system, take anti static precautions before touching anything inside, you can do this by touching a bare metal part of the case or PSU.

Press and hold in the case power button again, release the button then remove the CMOS battery, leave the battery out for at least an hour then put it back in, reassemble, connect the screen to the GPU, the keyboard and the power cord, press the power on button with your fingers crossed.

[Ijaaz]

Not too sure what the model name or number is as it came with the case. But I will try what you told me to do now.

[phillpower2]

(y)

[Ijaaz]

I left it for 2 hours and put it back and no luck

[phillpower2]

Doesn’t look good for the CPU I`m afraid

Only two things that I can suggest;

Try another known good PSU in case there is a problem with the 4 pin 12V ATX CPU power supply from the AZZA PSU, any test PSU must be at least 400W and preferably from a proven brand with at least a Bronze efficiency rating.

Remove both sticks of RAM and then try just one stick of RAM at a time in the slot nearest to the CPU, if no change, repeat the same test but this time try one stick at a time in the second slot.

Reminder, you must have a keyboard connected or the power on self test ( POST ) will fail.

[Ijaaz]

I don’t have another psu to test unfortunately and I already tried the ram in different slots and even 1 in both and none still same issue

[phillpower2]

If you can’t borrow a PSU you are going to have to take the PC to a local tech store or alternatively have a mobile tech come to you, there is nothing else that we can suggest here I`m afraid.

CPUs are not prone to failure with the MB being more likely to fail first, this means that something else looks to be responsible.

Had you been messing with any settings before shutting down yesterday.

Does the cooling fan spin up and stay running when you press the power on button.

Are the heatsink and cooling fan secure atop of the PSU.

[Ijaaz]

No settings have been messed with I turned off the pc the night before after doing uni work and the next day I came home from uni and turned it on and I encountered the problem.

Yes all fans are running when I power on even the gpu fans.

And yes the heatsink and cooling fan is secured on the CPU is what I think you mean not PSU

[phillpower2]

Do you leave the PC connected to the wall socket when it is not in use.

The CPU cooling fan running and the heatsink being secure goes some way to ruling out the CPU having overheated.

If you can’t borrow a PSU you are going to have to take the PC to a local tech store or alternatively have a mobile tech come to you, there is nothing else that we can suggest here I`m afraid.

The above is where we are at as other than a dead CPU a problem with the 4 pin 12V ATX CPU power supply from the AZZA PSU to the MB there would not normally be anything else that would indicate a CPU error, if the MB was dead the LED would not come on at all.

[Ijaaz]

Yes I do leave the PC connected to the wall however it is connected to a voltage regulator.

I also do not think it is dead CPU as prior to the issue the cpu had no signs of slowing down or not running as it should.

I tried the other 4 pin cable for the CPU and had the same result. As you said I don’t think the motherboard is bad as the ram and GPU is receiving power correctly and the debug led is coming on.

Only thing I can think of is the PSU not giving enough power to the system. I am trying to get a guy to come over to check it out and see what the actual issue is. Thanks a lot for your help.

[phillpower2]

I tried the other 4 pin cable for the CPU and had the same result.

I take it that you mean the the other half of the 8 pin ( 4 + 4 pin ) 12V ATX CPU connection, if yes, if the first 4 pin was bad so would the second be because they are on the same PSU rail.

You are making the right call by getting a local tech to take a look.

You are welcome and good luck (y)

[Ijaaz]

Hey I had a question, I noticed before I had this problem with the CPU debug LED that if the power goes down my bios settings would reset each time. I looked online and it says that it was a sign of a dying CMOS battery. I also read that a dead CMOS battery can cause bios related errors which might trigger the CPU debug LED and prevent booting. Can this be a possibility as to why my pc suddenly stopped working and the CPU debug LED came on?

[Ijaaz]

Okay forget my last question, I changed the cmos battery today and still same problem. I think that usually only applies to older systems as further research showed.

[Ijaaz]

Update:

Pc works now, got a new motherboard and now it works.