u/DavidkDavid

I was about to post this as a troubleshooting post, but I solved the issue and would like to share.

Most tutorials I watched involved pulling out RAM, GPU, various other components to narrow down what component is causing the problem. In my case, it was a SATA powered fan hub that I forgot to plug in again while installing the new power supply. Because it wasn't detecting that, it wouldn't display out or spin fans. My motherboard also displayed a CPU error on its troubleshooting LEDs. This is very weird but maybe this will be helpful to someone.

Note, if part of your troubleshooting involved removing the RAM, and you managed to boot with a different RAM configuration, you may also need to reset the CMOS to get it to boot with your original RAM configuration again.

I am upgrading two components on my homebuilt PC, the GPU and the Power Supply. GPU is going to RX 7900 XTX, and the PSU is going to a Gigabyte UD1000GM 1000 watt. Unfortunately, I didn't check that it had enough 8-pin slots, it only has two and the GPU has 3.

Can I therefore use the two cables, and just plug in the extra plug from one cable into the last plug? I've done a lot of googling and this *should* be fine (as shown in this diagram someone else posted linked below). But a lot of people have said it can lead to instability.

As a sanity check, I wanted to run it by you fine folks in hopes I don't have to swap out this shiny new PSU. Does anyone have experience trying this with high demand GPU's?

As a side note, it does have a 12v rail if there's some kind of voltage step down adapter out there that I could use. I've never heard of that being a thing but I'm sure I'm not the first to think about it.

https://www.reddit.com/media?solution=22a68a29c03dc74822a68a29c03dc748&js_challenge=1&token=bbbe4bf1c9a2b5160829c4be34da586158a3b5990caa1bd43a770c4960e7d04f&jsc_orig_r=&url=https%3A%2F%2Fexternal-preview.redd.it%2F4veUOhl1sfxjBFJT1017NzUbQmmNVFmDPDgmpmkFrjI.jpg%3Fauto%3Dwebp%26s%3Da589a3960e5864f9d2982f83ed547564fec3b7bb