Question Troubleshooting suspected bad MOBO

[clintone88]

Setup:
MOBO: Asus Prime X570-P AM4 ATX
CPU: AMD Ryzen 5 3600 6-core
PSU: OCZ ModXstream pro 700W
RAM: G.Skill Ripjaws V 8GB DDR4 3600 x2
SSD: 1TB WD Black SN770 (new today, previously 1TB Aorus NVME).
GPU: XFX Radeon HD 7850

Have had this system generally the same as it is for about 3.5 years with no issues, the PSU and GPU are about 12 years old.

Some time over the weekend windows shut down and failed to start back up. Tried repairing through the SSD, and then repairing through a USB media install, neither worked. Finally tried a completely fresh install, and it wouldn't install on the old NVME I had (giving "couldn't install in the location you chose" error). I wasn't able to get past this error after trying what I saw on forums, so figured I needed a new hard drive.

Went and bought a new WD NVME, came home and installed it and when I tried to turn on the PC, it spun up for about 0.5 seconds, then died. Absolutely no activity at any point after that when pressing the power button. No LEDs on MOBO, no spin up on PSU when pressing power, nothing at all.
So far I have tried:

1. Testing the PSU. Spins up and voltage readings are fairly within normal, (getting 11.74 instead of 12; 5.3 instead of 5; 3.3 is pretty spot on).
2. Tried using power reset instead of power button cable, tried using manual jumper.
2. Visual inspection of MOBO, checking connection of all cables, etc. Everything looks and feels OK.
3. Reset CMOS, removed battery and jumped power for a couple minutes.
4. Removed CPU and visually inspected, no broken pins, dust, TIM, etc.
5. Removed everything but CPU/cooler, power, and one stick of RAM.

At this point I'm assuming the MOBO is bad. I assumed it was the PSU at first since it's ancient and there's absolutely no hint of power in the system, but the test values don't seem far enough outside range to result in absolute failure.

Have I missed anything in troubleshooting the MOBO? I don't want to buy one and have it not be the problem, but at this point I'm stumped on what else it could be.

 

[Lutfij]

Welcome to the forums, newcomer!

PSU: OCZ ModXstream pro 700W
You should replace that PSU ASAP. Invest in a reliably built 650W PSU.

 

[clintone88]

Welcome to the forums, newcomer!

PSU: OCZ ModXstream pro 700W
You should replace that PSU ASAP. Invest in a reliably built 650W PSU.

Thanks for the input! That was my original thought and plan, but I wasn't sure if the problem was beyond simply the PSU given that I have no power whatsoever at the MOBO, and the PSU is at least showing signs of semi-functioning.

Do you think that the PSU could be the sole problem? Or is it more of an issue of the PSU needs to be replaced no matter what, and so start there.

 

[drea.drechsler]

Thanks for the input! That was my original thought and plan, but I wasn't sure if the problem was beyond simply the PSU given that I have no power whatsoever at the MOBO, and the PSU is at least showing signs of semi-functioning.

Do you think that the PSU could be the sole problem? Or is it more of an issue of the PSU needs to be replaced no matter what, and so start there.

That OCZ PSU is a very old design from around 15 years ago and probably not suitable for modern systems which puts so much more demand on the +12V rail. Older computers put more power demand on 3.3V and 5V rails, modern motherboards develop lower voltages with on-board VRM's from the +12V rail. Based on it's data plate it's effectively a 550W PSU when loading the two 12V rails together.

And design aside it may itself be a very old PSU which means resistors and capacitors have shifted values. If 10 years in age or older the PSU probably worked OK for a while but that component aging means voltages can briefly (very briefly) drop much lower than you're seeing when actually running dynamic CPU and GPU work loads so the system locks up. While it may not be the fault it does seem a very good starting place.

 

[clintone88]

That OCZ PSU is a very old design from around 15 years ago and probably not suitable for modern systems which puts so much more demand on the +12V rail. Older computers put more power demand on 3.3V and 5V rails, modern motherboards develop lower voltages with on-board VRM's from the +12V rail. Based on it's data plate it's effectively a 550W PSU when loading the two 12V rails together.

And design aside it may itself be a very old PSU which means resistors and capacitors have shifted values. If 10 years in age or older the PSU probably worked OK for a while but that component aging means voltages can briefly (very briefly) drop much lower than you're seeing when actually running dynamic CPU and GPU work loads so the system locks up. While it may not be the fault it does seem a very good starting place.

Thanks for the detailed response. The PSU has been in my own system for about 12 years, so it's at least that old and has been used almost daily that whole time. So time for a new one anyways. Went out and bought a new Corsair yesterday, so we'll see what happens when I swap them.