Question Computer turned off and now appears dead

[Ethan85]

Hi. So I built this PC 6 months ago and it has been working basically flawlessly with no lag/stuttering/artefacts/overheating etc until yesterday. While playing a random old game (Mechwarrior 5) it suddenly turned off. There was no sign whatsoever before this happened, no audio/visual anomalies/lag/slowdown/etc. When I try to turn it back on it will not even POST and only the fans + RAM LEDs turn on and the CPU EZ DEBUG led is showing red. Peripherals (USB keyboard LEDS) do not appear to turn on either.

Specifications:
MSI MAG Z790 Tomahawk WIFI (DDR5)
i9-13900KF
RTX 4090 (MSI brand)
GSkill Trident Z5 RGB 2x32GB
MSI A1000G PCIE5 1000W (Power Supply)
Noctua NH-U12A
Seagate FireCuda 530 2TB.

No overclocking.

I initially thought it could be the PSU but I have checked all the rails with a multimeter while its powered on and they all appear to be present and very stable (e.g. 12v comes up within 1 second of power on and stays at 12.01/12.02V). I have checked the 3.3V/5V/-12V/5VsB/PWRON rails as well and they appear to be there and at the required voltage. All the fans are working (heatsink + case fans + GPU fans).

I did have one strange thing happen with this PC a few months ago (this is why I suspected PSU mainly) so in the middle of the night it rebooted after doing an update but it could not reboot successfully. Turning it off and on it also failed to POST, except the VGA light was showing at that time instead... I simply turned the computer off for a while and when I came back it turned on as normal.

I'm not super experienced so I would really like to request some help to diagnose and fix this problem? I've never done an RMA or anything before, but I guess that some component here needs replacing for sure?

 

[XxDarkMario20xX]

I bought MSI A1000G PCIE5 1000W in march lasted until couple days ago when it started to turn off my computer instanly and wont power on . I would do couple checks on your computer like reseating the ram or try it with one stick and such. Also would try and do like an paperclip test!

 

[Ethan85]

Yeah I've been reading some very troubling reviews of that PSU dieing, seems to have happened to quite a few people... Is there some way to verify that the PSU is in fact busted (despite rails showing the correct voltages on my meter)? Or should my next step just be to buy a new one and try it/return it if it doesn't fix the problem?

I'm really confused what I should try first basically

 

[Dark Lord of Tech]

It's mot a good power supply. Hard to diagnose without a decent one.

 

[Viking2121]

Yeah I would blame the PSU, I've ran into a 850 watt PSU from MSI that one of my customers bought, and have a really flaky unstable 5v rail, RMA'd it and it was so bad the PSU would start fine, but random things would stop working or the system would crash.

I would blame the PSU in this case, avoid MSI, Get a name brand, you will have to spend some money on a good unit, but with a 4090, I suspect it wouldn't be too much of a problem to get a well known reliable unit.

Good Luck!

 

[Ethan85]

Thanks Guys, I have bought and fitted an HX1000i and still have the same problem :|

I guess the next thing to try is replace the mobo?

 

[Ethan85]

Thanks Guys, I have bought and fitted an HX1000i and still have the same problem :|

I guess the next thing to try is replace the mobo?

Well... replaced the MOBO with one that has Q-Codes and its showing Q-Code 00 on a ROG Strix Z790-E.

I'm at a total loss

 

[Ethan85]

Just in case anyone is interested the problem turned out to be the CPU, totally dead basically. I needed the help of a local computer shop to find this out. Have since replaced cpu and mobo by moving over to AMD... Quite an expensive malfunction overall :|