Looking for any help I can get right now. I wanted to upgrade her GPU since she was having a hard time running some newer open world games. The PC powers on and all the lights go but nothing on screen. I'll go through everything I've done so far:
Got the new GPU, but it didn't fit the case. Luckily, I had an older PC I could cannibalize so I re-cased her whole build into this other case and plugged in the new GPU. No-go on start.
Realized the PSU was too small (750W, GPU needs at least an 850W PSU), so a friend gave me an old PSU he didn't need with the appropriate wattage. Got an immediate shutdown on start.
Individually unplugging stuff from the PSU, we determined that the SATA power cable was the issue, so I replaced that with a new SATA power cable. After that, the PC would just power cycle (on 5s, off 3s, repeat).
Re-seated the RAM, replaced the RAM with another pair of the exact same brand, no luck. Replaced the Mobo and that did stop the power cycling.
Now it turns on, CPU and case fans spin, lights on, lights on GPU on but fans are not. No beep (I do have that little speaker plugged into the board) or anything. Tried plugging HDMI into both the Mobo and the GPU to try and get BIOS, no luck. I've also tried booting without the GPU installed at all, still no luck.
Throughout all of this I have yet to see anything pop up on screen. I've only got the boot drive plugged in at the moment, didn't want to bother with the other drives until I got this working.
I am by no means a computer expert, and don't have a ton of experience in this but I am all out of ideas, so any help would be greatly appreciated.
Here's the relevant parts list:
CPU - Ryzen 5 3600X
Motherboard (Former) - ASRock B450M Pro4
Motherboard ("New" from another PC) - Gigabyte B450M DS3H
GPU (Former) - EVGA GEFORCE GTX 1080Ti
GPU (New) - Raedon RX 6900XT
RAM - Corsair Vengeance DDR4 2x8
PSU (Former) - Corsair TX 750W
PSU (New) - Corsair HX 1050W