Unique PSU/MB combination stopped working

[Master_X]

Hey guys I am the PC / electronic guy here around and some days ago my brother told me his PC stopped working. Absolutely nothing pressing the case power button. I figured out very fast it's a mainboard and/or PSU issue. Now I did much testing and got completely confused. It really seems this exact combination does not want to work anymore. (It was working fine for years) Heres why:

My brothers PSU works flawless with other systems. Also my brothers mainboard works flawless with other PSUs. After I found about this I just put together his hardware again and grounded the green PSU on wire. Then I pressed the case power button. Et voila the computer starts again. I have no real idea anymore since this is kind of weird. 

 

Somehow it seems in this combination the mainboard does not signal the PSU to turn on anymore. I don't think it matters really much but it's a Thermaltake Hamburg 530 and a Asrock A320M-HDV.

 

Did I forget about anything or anyone has another idea to this?
 

Thank you

[Somerandomtechyboi]

Just replace the psu

If you dont wanna spend a fortune on a new one just buy used, quality 750/850w gold units like the rm(x) or equivalent are around 40-60$ used and there are also cheaper used units available

[Master_X]

I have enough hardware thats not the problem. This is the troubleshooting section and I just look for another brain thinking about it or maybe someone had a similar experience.

 

Of course replacing will fix it.

[keskparane]

Perhaps there is an issue with another cable or hardware device other then the PSU or MB and the PSU is not starting because it detects a short/problem elsewhere? EG CPU or PCIE cable. Are all the cards in the original machine properly seated?

[Master_X]

14 minutes ago, keskparane said:

Perhaps there is an issue with another cable or hardware device other then the PSU or MB and the PSU is not starting because it detects a short/problem elsewhere? EG CPU or PCIE cable. Are all the cards in the original machine properly seated?

Do you think my other 2 PSUs I tested would not get triggered by this? Both worked fine even with graphics card. For testing I also removed the graphics card as variable. The mb has only CPU 4 pin and ATX 24 pin connected.

 

Edit : Yes I think all cables are fine

[keskparane]

10 minutes ago, Master_X said:

Do you think my other 2 PSUs I tested would not get triggered by this? Both worked fine even with graphics card. For testing I also removed the graphics card as variable. The mb has only CPU 4 pin and ATX 24 pin connected.

 

Edit : Yes I think all cables are fine

I just thought that if you were only testing with PSU and MB you might miss a problem caused by another hardware device. If you are also using the same drive, cards, ram, etc then you have done a proper test.

 

Next I would reset the BIOS in case it's trying to force a funny voltage or something and only the PSU is sensitive to it.

 

I'm also assuming you're using the same case and that you've eliminated the case power switch as a problem.

[Master_X]

2 minutes ago, keskparane said:

I just thought that if you were only testing with PSU and MB you might miss a problem caused by another hardware device. If you are also using the same drive, cards, ram, etc then you have done a proper test.

 

Next I would reset the BIOS in case it's trying to force a funny voltage or something and only the PSU is sensitive to it.

 

I'm also assuming you're using the same case and that you've eliminated the case power switch as a problem.

Yes you are right. I tracked it down to the mainboard and PSU but only in that specific combination. With other PSU's the mainboard works and with other mainboard the PSU works. Never ever had a case like that. The bios got resetted multiple times. I tied to get some RAM working.

[leclod]

1 hour ago, Master_X said:

After I found about this I just put together his hardware again and grounded the green PSU on wire. Then I pressed the case power button. Et voila the computer starts again. I have no real idea anymore since this is kind of weird.

Does this mean the original psu works fine when grounded with an additional cable ?

[Master_X]

The whole PC at least boots when green connected to ground and power case button is pressed. Also OS loads fine. Did not any further testing.

[Master_X]

Update : I ordered a used Thermaltake with the same model number (there are different ones for the same unit). PC works again. Anyone any idea how to troubleshoot this further? Clearly this is a PSU issue but the PSU itself works. It only won't be turned on by that mainboard anymore.