Help needed – PC/NAS failed and now won’t even start to POST.

Hi guys – I’ve run a NAS system for a few months with in a Jonsbo N3 case, CWWK Q670-NAS 8 bay motherboard, Intel i9- 14900K CPU and 48Gb of Crucial DDR5 memory.

It started giving me some errors on one of the CPU cores so I started to troubleshoot. I rebooted to Memtest and ran that for a while with no errors.

Then I booted to a Linux bistro so I could run OCCT which also ran ok with no errors – I was running a test using Prime95 when the system just shutdown immediately. Since then I have replaced the PSU, CPU and motherboard and nothing works. The system simple clicks once, the PSU, CPU and system fans all spin up for a second and then stop and nothing else happens.

I’m at a complete loss as to what to try next.

Please can someone give me a pointer or two….

Tagged: NAS

NAS data recovery

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Jace Elric

Participant

February 27, 2026 at 8:54 am

At this point, the one-second power on and immediate shutdown points to a short circuit or power protection issue rather than a CPU stress failure. Since the PSU, CPU, and motherboard have already been replaced, the most likely causes are a case short, incorrect or mixed PSU cables, bent CPU socket pins, faulty or incompatible RAM, or something metallic behind the motherboard causing a short. The next step is to remove the system from the Jonsbo N3 and test it outside the case with only the CWWK Q670-NAS, the Intel Core i9-14900K, one stick of RAM, cooler, and PSU connected, then start it by shorting the power pins manually. If it stays on, the case or mounting hardware is causing the problem. If it still shuts off instantly, inspect the CPU socket carefully for bent pins, confirm the 24-pin and CPU EPS cables are fully seated and not mixed from another PSU, and test with a known-good RAM stick. One of these is almost certainly triggering PSU protection and preventing POST.

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