Finished a PC build, nothing happens when I turn it on.

[steinarey]

I just finished upgrading my 6 year old rig (new everything except case) and when I go to turn it on, the fan on the PSU clicks on and does half a spin and then off. No lights on the motherboard, nothing.

 

Tried so far:

Used QFlash Plush to upgrade the BIOS, that worked as expected, QFlash light blinking and all.

Re-seat the memory (and removing one stick and trying).

Disconnect the GPU power to see if it shows an error.

Check the power cables on the motherboard and PSU.

 

Spec:

i9 13900K

GeForce 4070Ti

Corsair 32GB DDR5 2x16GB 6000MHz Vengeance CL36

Seasonic Focus 850W Gold+

Gigabyte Z790 Gaming X AX motherboard.

 

I did check the pins on the board before placing the CPU in, made sure nothing was bent out of shape.

One thing that I suspect. The motherboard has two 12V connectors but I only have one plugged in (can't find the second 4+4 pin cable...). From what I've read, that shouldn't be strictly needed but I am not sure.

 

Help :*(

[RONOTHAN##]

Leave everything else plugged in, but try to do the paper clip test for the PSU. 

https://www.silverstonetek.com/upload/downloads/QA/PSU/PSU-Paper Clip-EN.pdf

 

If it continues to immediately shut off after doing it, unplug every connection and try again. If it still does, the PSU is dead. If the fan starts to spin up after everything is disconnected, there's a short circuit somewhere and start plugging things back in one by one and trying to figure out where it is. If it comes on the first time doing the paper clip test with everything plugged in, it's probably a dead motherboard. 

[steinarey]

27 minutes ago, RONOTHAN## said:

Leave everything else plugged in, but try to do the paper clip test for the PSU. 

https://www.silverstonetek.com/upload/downloads/QA/PSU/PSU-Paper Clip-EN.pdf

 

If it continues to immediately shut off after doing it, unplug every connection and try again. If it still does, the PSU is dead. If the fan starts to spin up after everything is disconnected, there's a short circuit somewhere and start plugging things back in one by one and trying to figure out where it is. If it comes on the first time doing the paper clip test with everything plugged in, it's probably a dead motherboard. 

I'll give it a try when I get back to it. I had this PSU in another case before moving it over, worked fine there so I doubt it's the PSU, but it could be a short. Hope so rather than a dead mobo...

[Alex Atkin UK]

Also if PSU is good, disconnect the GPU entirely and try using iGPU.

[spunk.funk]

If everything is new except the PSU, then that might need to be replaced as well

[steinarey]

I did the motherboard paperclip test and the PSU started. Then I went plug by plug until I realized my error...

I had a molex cable from the old PSU connected. Thankfully the PSU decided to shut off instead of breaking so I replaced the cable and now everything seems to be working fine. Thanks to all!