Question PC refuses to post when GPU is plugged in?

[smoothconch]

When my GPU is plugged into PCIe cables, the only component that will turn on is the RAM led. When I remove the PCIe cables but leave the GPU plugged into the motherboard, all of the components in the PC turn on, but the computer refuses to post.

I got this build to post last week, but I had the stock cooler on my graphics card. I have since removed the heatsink and fans and replaced thermal pads and paste. I'm really hoping I didn't destroy my card when I put on the waterblock because I was very careful and meticulous, and the process went over very smoothly. In an attempt to fix this, I have tried:

-Checked every cable twice to ensure they are all seated and in the correct place
-Removed the GPU backplate
-Changed out PCIe cables

At this point, I can really only conclude that my GPU is fried. Which sucks, because I was extremely careful in installing the waterblock. Please, if anyone has ANY suggestions, I would love to hear them.
My build:

CPU: Ryzen 7 3700x
GPU: Zotac 3070 Twin Edge OC White
PSU: Corsair SF600 Gold
Motherboard: GIGABYTE B550I AORUS PRO AX

If in any way possible, I would love to salvage this card. Additionally, it is worth noting that my custom loop has already been filled, which does make it more complicated to move things inside the case (especially because it's the coolermaster nr200p).

Thanks in advance!

 

[kurdtnz]

I dont know if it could have any kind of impact but your card does say it recommends a 650w power supply?

 

[smoothconch]

I dont know if it could have any kind of impact but your card does say it recommends a 650w power supply?

Yeah but I'm fairly certain it isn't a power supply issue because 1) My total system voltage should run somewhere around 450W on the high end (RTX 3070 only pulls 220W), and 2) The computer posted just fine before I replaced the cooler