So I grabbed another "parts or repair" GeForce 6600 Universal AGP. This time just the normal non-GT version, built by PNY. This one was listed as working and displaying video, but with a bad fan. That was a lie, but not in the way the seller likely meant.
It works flawlessly. You know when the fan doesn't spin? When the Molex power isn't connected, because again these universal AGP 6600 pull 100 percent of their power from the Molex. Its not like well literally every other card I know of that will display an error message or beep if the molex isn't connected. These just do nothing.
So the seller thought the card was completely dead, decided to lie and list it as working but with a bad fan, when in reality it works perfectly but he was too incompetent to discover this. Hence how I got another AGP 6600 for $25.
I also got around to testing the $5 Quadro FX3500s, and one of them worked, one of them was completely dead, and the other had issues and someone had already tried to reflash it to a 7950GT. Now as you might imagine, reflashing a 450MHZ 20 pipe G71 card with 256MB of memory to a 600MHZ 24 pipe card with 512MB of memory didn't work out that well. G71 on PCIe is laser cut, so there is no reenabling pipelines on these. I reflashed it back to Quadro 3500 but either it already had issues or the 7950 flash blew out a memory chip because it was still artifactin like a mofo. For $5 each shipped I'm not complaining 🤣 I knew what I was getting into with that purchase.