Question Dead PSU? Motherboard? CPU? All three???
Question Dead PSU? Motherboard? CPU? All three???
My primary system, which had been functioning properly until recently, is currently non-operational—no POST, no debug lights, nothing at all. I've reviewed and attempted various troubleshooting steps such as the "No POST", "system won't boot", and "no video output" lists, but none have resolved the issue.
Specific details:
Processor: i9-10900k with EK 240mm AIO
Graphics Card: MSI z490 Gaming EDGE Wifi
Power Supply: Thermaltake ToughPower GF1 850w PSU
Memory: G.Skill Ripjaws 16GB DDR4 (x4)
Display: EVGA FTW 3090
Storage: Samsung 9800 Pro M.2
Case: NZXT H510
Initial assumption was a failing power supply. I plan to replace it and test, but so far both PSUs appear functional. Next, I suspect the motherboard might be the culprit. I've set up a breadboard to verify functionality, but it still doesn't POST or illuminate debug lights. I've tested each RAM stick separately and switched power cables without success.
Considering the CPU as another possibility, I'm hesitant due to the lack of debug light activation after removing it. To avoid further risk, I'm contemplating borrowing a colleague's machine to test the PSUs. Overall, I worry I might be misdiagnosing the problem by swapping components prematurely.
Any advice or alternative perspectives would be greatly appreciated.
Have you attempted starting with the graphics card fully detached from the board? Not merely disconnecting it from power and display cables, but removing it entirely. Have you tested a wall outlet on a separate circuit? Used a multimeter to verify there are no major issues there? If using a power strip or surge protector, remove those and connect directly to the wall. Would also consider removing any storage devices like M.2 drives to rule out internal shorts affecting protections on the board or PSU. Are you manually jumping the power pins or using the case switch to energize the PSU and board?
Hey Darkbreeze, thanks for your prompt response.
I’m using just the CPU, one stick of memory, and the PSU—no GPU or M.2, and everything is out of the case with the motherboard on an anti-static mat. I’m plugged directly into a wall outlet; I don’t have a tester to verify the voltage, but it worked for other devices recently.
I’m manually jumping the power pins using a screwdriver. I’ve also checked the front panel leads and switch from the case, but neither seems to make a difference.
Well, it doesn't seem too complicated after all.
Two distinct power supplies gave the same outcome.
Two different motherboards produced identical results.
I tested all four DIMMs in the A2 slot individually, and the outcome remained the same.
No changes occurred with any drives or other connected devices.
What remains is just the CPU; this is something rare, as CPUs typically fail only after user-induced damage or events like power surges or lightning strikes. Still, it can happen occasionally.
Although I must note this, it's very unlikely you purchased a brand-new Z490 board unless it was labeled as "new old stock," which has been discontinued for some time. So I might not completely eliminate the possibility.
Where did you acquire the second board from? Was it supposed to be new or used?
Just for fun, you might also consider using a different power cable to the PSU if you haven't already done so. Also, verify that the outlet is functioning properly by testing it with a lamp.
Roger that. The Z490 board is refurbished from NewEgg, but I remain doubtful since the debug LEDs don’t activate (though not on my original unit either). According to what I know, those LEDs should illuminate when there’s a problem with the CPU or other parts. I’m confused about why I’m not seeing them even when the CPU is faulty—unless I’m misinterpreting how they function.
Outlet/Plug: I thought so too, and also tested another PSU power cable—no change. The outlet I’m using works with other devices (charged my laptop last night). To confirm, I tried a lamp as well—it lit up.
So it seems the CPU is likely the issue now. It’s turning into a frustrating search for the right fix.
This affordable CPU locator helps you assess if the purchase is justified. You can resell the CPU to recover your cost or combine it with a motherboard for a bundle sale. Alternatively, keep it for future troubleshooting. It offers valuable insight at a lower price compared to other methods.
Good decision on the affordable CPU! I have a friend who wants to build a machine for his son; I could give it to him if he hasn’t made one yet. Otherwise, as you mentioned, a solid troubleshooting kit would be perfect.
CPU purchase; reviewing the emails from my machine-building days, it seems I bought most parts back in November and December 2020 (and yes, the CPU was brand new).
The only issue is that I can’t find the receipt or email for the CPU.
Well, that's unfortunate, but it would still be covered under warranty as long as you have any documentation related to your purchase. An invoice, receipt, credit card statement, or similar proof should suffice. You might also reach out to the seller or check their website for a copy.
Roger that - began on that route this morning.
Appreciate all your ideas and assistance! That should bring a bit of clarity to things!