[SOLVED] PC died overnight; No power in the motherboard.

[CasualPeachSaxNew]

Ok so my PC was working fine yesterday. Got to my office this morning and noticed through the glass that my motherboard's lights were off, tried powering the computer and it didn't work.

I tried:

1. Unplugging all cables on my PSU and motherboard and re-plugging.
2. Paperclip test on the PSU which resulted in the fan running for maybe 3-5 seconds and then slowing down till full stop. I wasn't sure how to interpret that info as a pass or a fail.
3. Tried to look for busted capacitor and didn't find any on the mobo. Noticed that some (of what looks like) capacitors inside the PSU have some sort of small black stain on them but it's hard to say whether its a normal marking or not.
4. Tried different wall plugs.

So yea, I'm ready to replace either part but I wanted to know if someone knew more about this and would have troubleshoot ideas or knows whether the problem is the mobo or the psu?

Specs:
GPU: NVIDIA GeForce RTX 2080 Ti
CPU: AMD Ryzen 9 3900X
CPU Cooler: NZXT Kraken x62
Motherboard: GIGABYTE X570 Aorus Master
RAM: G.Skill Ripjaws V Series 64GB DDR4-3200 [16GB x 4]
PSU: Corsair HX Platinum 750 W80
Case: NZXT H700i ATX Mid Tower
SSD [Windows 10]: Samsung 970 Pro 1TB
HDD: Seagate BarraCuda Pro 4TB 3.5” 7200 RPM

 

[jonnyguru]

Paperclip test on the PSU which resulted in the fan running for maybe 3-5 seconds and then slowing down till full stop. I wasn't sure how to interpret that info as a pass or a fail.

That PSU has a zero RPM fan mode. So if there's little load or low temperatures, the fan is only going to do an initial test spin then turn off.

Tried to look for busted capacitor and didn't find any on the mobo. Noticed that some (of what looks like) capacitors inside the PSU have some sort of small black stain on them but it's hard to say whether its a normal marking or not.

You're not talking about the RTV in the PSU, are you?

Corsair HX750 PSU Review - KitGuru

The Corsair HX750 supply is a performance unit, featuring ultra silent operation under all condition

www.kitguru.net

 

[jonnyguru]

So yea, I'm ready to replace either part but I wanted to know if someone knew more about this and would have troubleshoot ideas or knows whether the problem is the mobo or the psu?

Do you have a multimeter?

If the mobo lights are out, there's no +5VSB. Easy thing to check is to probe the +5VSB and see if there's voltage. If there is, the problem is likely the motherboard. You can take this further by then jumping the 24-pin with the paper clip again and testing the other voltages.

 

[CasualPeachSaxNew]

Do you have a multimeter?

I don't believe I do, but I'll get one from amazon to check this out, thanks!

 

[CasualPeachSaxNew]

That PSU has a zero RPM fan mode. So if there's little load or low temperatures, the fan is only going to do an initial test spin then turn off.

You're not talking about the RTV in the PSU, are you?

Good to know!

I don't know what an RTV is but I'll see if I can attach screenshots, it's on multiple similar cylinder-shaped thingies (that look like bigger motherboard capacitors.
Two image here might help.

https://imgur.com/a/ECzuWqK

View: https://imgur.com/a/ECzuWqK

 

[jonnyguru]

I don't know what an RTV is but I'll see if I can attach screenshots

That's why I provided the link showing the inside of the PSU.

Some people see the RTV (the "glue" you see in those pictures on the page I linked) and mistakenly think it's from something leaking.

it's on multiple similar cylinder-shaped thingies (that look like bigger motherboard capacitors.
Two image here might help.

https://imgur.com/a/ECzuWqK

View: https://imgur.com/a/ECzuWqK

Ok. That's just magic marker. In the QC stage, a person goes over the whole PSU and checks each capacitor to make sure it's inserted with the correct polarity. Once the cap is checked, they mark the top with magic marker.

 

[CasualPeachSaxNew]

That's why I provided the link showing the inside of the PSU.

Some people see the RTV (the "glue" you see in those pictures on the page I linked) and mistakenly think it's from something leaking.

Ok. That's just magic marker. In the QC stage, a person goes over the whole PSU and checks each capacitor to make sure it's inserted with the correct polarity. Once the cap is checked, they mark the top with magic marker.

Oh I just noticed, sorry I probably glanced over it thinking it was a link within your signature text :\

And awesome, that reassures me

Thanks a lot, I'll get a multimeter tomorrow so I can check the voltage!

 

[CasualPeachSaxNew]

If the mobo lights are out, there's no +5VSB. Easy thing to check is to probe the +5VSB and see if there's voltage. If there is, the problem is likely the motherboard. You can take this further by then jumping the 24-pin with the paper clip again and testing the other voltages.

Ok so I followed a youtube tutorial and here are the result. I presume from what you told me that I need to replace my motherboard.

Also, do you know how to prevent that in the future? Maybe plug my computer through a safe powerbar (it was directly plug in the wall)?
Also, I'm in Canada if that helps with Voltage conventions.

Black in pin 24, Red in pin...:
13: 3.28V
14: -12.11V
21: 4.97V
22: 4.97V
23: 4.97V

Black in pin 15, Red in pin...:
1: 3.27V
2: 3.27V
4: 4.97V
6: 4.97V
9: 4.97V (+5VSB)
10: 12.05V
11: 12.05V
12: 3.28V

Thanks again for the help

 

[jonnyguru]

Also, do you know how to prevent that in the future? Maybe plug my computer through a safe powerbar (it was directly plug in the wall)?

If it were something like a surge, lightning strike, etc., it would be the PSU dead. Not the motherboard. So a surge strip wouldn't have helped you. Sounds like just a defective motherboard.

 

[CasualPeachSaxNew]

If it were something like a surge, lightning strike, etc., it would be the PSU dead. Not the motherboard. So a surge strip wouldn't have helped you. Sounds like just a defective motherboard.

Awesome, big thanks for the help!

 

[CasualPeachSaxNew]

Ok, so I feel stupid not doing so earlier, but I google my issue with my specific motherboard and turns out its a re-occuring issue. All I had to do was remove the CMOS battery for a minute to let the power drain out and put it back. I've got power again!