Somehow plugged an 8 pin CPU power cable into a GPU PCI slot

[hast1996]

I'm very new to PC building, and when I got my final component, my GPU, I had plugged in my CPU power cable to it and turned my pc on. It didn't start, but there was a very, very brief crackling noise from the PSU, and I removed the cable to see if there was an issue, which there was. I switched out for the right PCI cable, but now if I plug my CPU cable into the correct spot on my motherboard, my pc will run for about 20 seconds, restart, and then continue this process. This does not happen when the cable is not connected.

I'm getting no signal on my monitor either way, so I cant tell how everything is running, but from the looks of things, everything in my pc, fans included, are running just fine.

I'm certain this cable is fried, but I'm worried that my motherboard, psu, and or my gpu might be as well, even if they dont seem to be. It was a incredibly stupid mistake I made and I'm feeling very dismayed at the moment, but if everything isnt broken but the cpu cable, should that be what allows me to finally use my pc and get a signal for my monitor?

My motherboard is an AsRock X370 Killer SLI/ac ATX AM4
My GPU is a NVIDIA GTX GeForce 1080 Gounders Edition
My PSU is a Corsair RMx 750w
My CPU is a Ryzen 5 1600x

 

[RememberThe5th]

As far as i know the CPU and PCIE power cables are basicly same pinout otherwise they should have different notches to grab onto the female plug.
If you can try out the components on other/friends PC, like ram/GPU and CPU if possible.
Or borrow an PSU and rule out that your PSU is broken.

 

[hast1996]

I dont have access to any other pcs in my area unless I go to a few limited stores, which I might have to do once I get a replacement cord.

 

[RememberThe5th]

Have you tried to clear the CMOS after you plugged everything right?
Usually remove the battery, unplug the PSU from wall then switch it on, press and hold power button for 30s~ and then switch psu OFF and then plug it into wall and switch it on. And now you can try to power up the PC.

If the motherboard came from shop do you see any sticker on it saying like P4.60, 1.20 and similar?
If not then there might be an issue that your CPU is not supported, unless you bought it together or asked.

 

[SkyNetRising]

It is not physically possible to put EPS 12V 8pin connector into PCIE 8pin socket.
If you somehow managed to do it ( I highly doubt that), then your graphics card is dead for sure, possibly PSU also.

Here is the pinout of those connectors. They are basically inverted. Where one connector has +12V, the other has ground.

 

[hast1996]

I haven't tried clearing the CMOs yet, I'll try that next. I dont see any sticker like that, but I'm very certain my cpu should be compatible with my motherboard. It's an AM4 CPU and the CPU socket accepts AM4s and it fit like a glove.
The cable seemed to fit, and I dont know how I must have got it down easily, but when I flipped the switch and powered it on it did produce that brief crackle from the psu that I checked. Guess I've lost a load of money over my dumb mistake.

 

[RememberThe5th]

Weird, then my PSU is cheaped out by far xD, since i plugged the "CPU" 4pin into GPU and PCIE into motherboard.

Well sorry if i answered you wrongly.

 

[AniChatt]

I have tried somewhat similar during my early days of PC building. I have used the PCIe power cable in CPU power socket and tried to turn on the PC. It was Seasonic X series power supply and the psu not turned on. Tried repeatedly before found this foolish mistake. This is something a good quality PSU should have to save itself and the components from idiots (No Offence Please!). So it means Seasonic X is better than corsair RMx.
What ever I would recommend you to test the PSU first from any nearby store. It is unlikely the cable has damaged. Once you confirm it is ok then you have to check rest of the components. But as Skynet said, it is different, even don't try to put a PCIe modular cable in the CPU power socket of the PSU and the other end to mobo EPS for this different config of connection.

 

[hast1996]

No offence taken. I was planning to bring this to the store soon, but I think it could be the cable since the power seems to be fine until its plugged in, though I'll be sure to still check the PSU just in case.
Though if as he said, the gpu is fried for sure, I might be too dismayed to really keep trying honestly. It was a huge investment and it really sucks knowing my incompetence probably ruined it.

 

[SkyNetRising]

Well - you can't be 100% sure about anything until you test it.

I'd start with different working graphics card and different working PSU. If that doesn't work, then there's issue with motherboard.
Then test graphics card in a different pc (with capable enough psu inside). Then you'll know, if GPU is fried.
With PSU it's a bit more tricky. If it is damaged, you might also damage anything else you connect to it. Safe way of testing it would be with multimeter.

 

[hast1996]

All I can really do is go to the local stores and see if they can test my components for me, though I dont really have my hopes up all that much.
Thanks to everyone for answering though, I really appreciate it!