PC wont boot, no POST

funkyuser · 28-03-2025 05:54PM #1

Today PC won’t boot doesnt POST, no beeps, no display signal, no numlock or capslock lights working

Case fan turns, CPU fan turns, GPU fans turn briefly, RGB LEDs come on

Was working fine the night before, it may have auto rebooted for windows update and never fully powered up again.

PC build can be found here,

https://www.boards.ie/discussion/2058239961/new-build-advice#latest

Motherboard is Gigabyte B550 AORUS ELITE AX V2 ATX AM4 Motherboard

Motherboard PCB is rev 1.1

Manual is here:

https://download.gigabyte.com/FileList/Manual/mb_manual_b550-aorus-elite-series_1503_e.pdf?v=dfe93ebb99075c5b2fec6247ebaf1008

i did add extra ram a year ago and it worked fine

The CPU did have some over heating events and would have shutdown sometimes, I eventually discovered the CPU fan was intermittently working and recently replaced it with a warranty replacement, and it worked fine since. I monitored the fan RPM and it was working fine

I updated the BIOS a year ago, no problems with that it seems.

I have tried the following things:

Tested a monitor, HDMI cable and keyboard with an old PC, all ok
Unplugged all other external peripherals and tested same monitor with the faulty PC, still no boot, no POST, no beeps, no display signal, numlock and capslock lights not working
Plugged in USB midi controller to all USB ports, controller lights up, so all the USB ports seem to have power
Also tried removing GPU, no change
Removed all RAM and GPU, no change, except the RGB on the CPU fan doesnt light up
Reinstalled GPU tried one RAM stick at a time, no change
Replaced CMOS battery, no change
I have not tried shorting the CMOS jumper pins yet for a BIOS reset
FYI motherboard has two m.2 SSDs installed, have not yet tried removing them

minitrue · 28-03-2025 06:19PM

Clearing the CMOS was one of the steps I would have mentioned. Certainly worth trying.

No gpu isn't likely to work in any sense as the Ryzen 5700X doesn't have a gpu. If you had access to a working compatible graphics card to swap in, or if the current one can go in the old PC, that could at least confirm the gpu isn't the problem.

It doesn't look like the board has any debug leds to offer a clue :( Can you find a "pc speaker" to hook up to it's header to see if you get any beeps out of it?

You could try using the bios flashback to update/reflash in case it somehow got corrupted.

funkyuser · 28-03-2025 08:04PM

shorted the CMOS pins, no change
took the working 1660ti from old PC installed it in new PC, no change
took the beeper cable from old PC and installed in new PC, no change, no beeps
took the 3070ti from new PC installed in old PC, old PC boots ok
not sure i want to try that BIOS update thing yet, thinking i should just build a new PC not sure if AM4 or AM5

funkyuser · 28-03-2025 08:22PM

old PC is

MOTHERBOARD: MSI B450M PRO-VDH PLUS: M-ATX w/ USB 3.1, SATA3, 1x M.2

BIOS Version: 7A38v9E (supports 5700X)

https://www.msi.com/Motherboard/B450M-PRO-VDH-PLUS/support#cpu

CPU: 2600x

GPU: 1660ti

PSU: 650 watt

should i try move the 5700x and 3070ti to the old PC, would that work? I do have a fresh tube of paste, no wipes to clean old paste though.

minitrue · 28-03-2025 09:06PM

Apart from trying bios flashback the only other thing coming to my mind right now would be to unplug the psu and pop the cmos battery and leave it for a while (like half an hour). That should both make sure the cmos gets cleared and sometimes weird things happen that only clear when all the power drains.

You seem to have confirmed it yourself that the 5700x will work in your old PC and 650W should be plenty. As mentioned in another thread even just some vodka on kitchen roll will do to clean up the old paste.

Of course there's no clarity yet (to me anyway) what's wrong with your PC, given you spoke of overheating issues maybe the cpu is the problem not the board. You can certainly try throwing the 5700x into the old PC to try to nail that down then decide what you want to do next. As long as you don't leave it running too long or put any load on it you don't even have to care about the paste while testing or even bother fully attaching the cooler, just having it sitting on top while it boots up long enough for you to see if it gets to the firmware or not is ok. You can even disconnect any drives while you are messing around just to make sure all it can't even try to boot into an OS ;)

dan_ep82 · 30-03-2025 12:14AM

CPU will work in the old board if it has the right BIOS. I would do that to rule out a bad cpu or mobo.

Before all that though I'd probably try one stick of ram ( one at a time to rule out each stick) and all but one NVME

funkyuser · 30-03-2025 02:53PM

I'm using currently using my old PC for gaming right now. It has a 2600x and I have installed the 3070ti from the new PC.

I've ordered a 5700x and I'm probably going to put that in the old PC with the 3070ti, because I just want to minimise downtime for now.

I'm thinking I might use the 2600x in the new PC for testing and then see where I go from there

FYI this is a photo of the BIOS screen on the new PC a few months ago. I was getting this error sometimes on reboot, not sure if its related

motherboard on new PC is a Gigabyte B550 AORUS ELITE AX V2 ATX AM4

https://photos.app.goo.gl/35ZR8w4zQyxbgrLh7

In future i will pay close attention to CPU temps and fan RPM and set alarms. Cant remember what the temps were but I do recall it was at the high end, maybe i should have repasted it.

minitrue · 30-03-2025 03:31PM

Unless I was blind the new motherboard doesn't support the 2600x which is why I only mentioned putting the 5700x in the old board to test it :(

Raichų · 30-03-2025 03:33PM

if there’s no attempt to even post and no sign of life I reckon the MB is dead OP.

funkyuser · 30-03-2025 04:14PM

used the motherboard warranty checker, it expires next month

I will contact support before I do anything else, maybe they will ask me to QFlash it we'll see

Dcully · 31-03-2025 09:20AM

"FYI motherboard has two m.2 SSDs installed, have not yet tried removing them"

Had something like this happen my old PC after it was idle for a few months.

The young lad wanted to game on it but had issues similar to what you explain and i tried everything.

I had given up until was thinking some days later maybe i should unplug the 3 SSDs one by one and low and behold one of the SSDs was the problem.

7+ months later the old rig with 8600K and 1080TI is geting gaming use every day and college work as a virtual machine and still going strong.

If you still have not i would try disconnected each SSD one by one.

funkyuser · 02-04-2025 05:17PM

Its booting again, all is OK, thanks for you help.

Support asked me to update BIOS with QFlash and its working now.

PC wont boot, no POST

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