Remove it and try the card without it, if everything else is OK it should work. You can replace it with a 4.7uF-10uF 6.3V 1206 cap.

Welcome to the forum! 😃
That's a ceramic capacitor and it helps with stabilising power required by closeby chips.
It likely shorted and it's plausible this would cause issues. It looks a bit burnt as well which means the pads underneath may lift when you remove it so be careful.
sdz said all there is to say about your options in repairing this defect.👍

Hi,

I removed the part and it works now better but still not. I now See the RAM in the Driver and Driver Tab will Not Crash randomly.
But unreal still complaits and Halflife wont Go further than "loading".

Are there any Things that i should Check that are Always broken?

The big chips often develop bad solders with some (sometimes a lot of) pins coming loose from the board. I use a needle to gently skate it across the pins and the loose ones will easily show up. Good amount of flux and clean tip with a flat edge will be able to get things soldered down properly again but if you have not worked with 0.5mm pitch parts before you really want to exercise on some other board with minimal importance to learn the process.

Also looks like some form of corrosion on de pci connector, make sure all the contacts are clean.

Thank you all so far!

I found a pin that was loose, but on further inspection it shows, that it is soldered to the pad, but the pad floats on the PCB... But there is connection between this pin and the other side, so it is connected. I resoldered a few pins that seemed suspicious.

I then tried mojo from the SDK and it detected everything fine, but Unreal would still error out at start with a 3dfx expected, not found error. Hm.
In Save-Mode Unreal seems to run in windowed mode, the V1 gets warm and I have a normal 3D image.

Edit:

meljor wrote on 2023-01-22, 09:47:

Also looks like some form of corrosion on de pci connector, make sure all the contacts are clean.

I cleaned them after soldering, that was unfortunately not the issue.

Did you replace the original suspicious capacitor? Maybe it is crucial to operation.
Also are you using original drivers or something like fastvoodoo that overclocks the card? Some aren't stable with those?

Not yet.
I am using the normal 3dfx driver (Graphics Driver kit Version: 3.01.00)

I logged the initialisation with mojo, maybe someone can see something obvious?

sst1Init Routines: InitCode $Revision: 8 $
sst1InitMapBoard(): BoardsInSystem = 1
sst1InitMapBoard(): vAddr:0xfc000000 pAddr:0xfc000008 Dev:0xc Board:0
sst1InitRegisters(): Setting TREX-to-FBI FIFO THRESHOLD to 0x8...
sst1InitRegisters(): Setting PRELIM FT-CLK delay to 0x8...
sst1InitRegisters(): Storing TREX0INIT0=0x5441
sst1InitRegisters(): Storing TREX0INIT1=0xf420
sst1InitRegisters(): Storing TREX1INIT0=0x5441
sst1InitRegisters(): Storing TREX1INIT1=0xf420
sst1InitRegisters(): Storing TREX2INIT0=0x5441
sst1InitRegisters(): Storing TREX2INIT1=0xf420
sst1InitRegisters(): Setting up FAST DRAM Configuration
sst1DeviceInfo: Board ID: Obsidian GE
sst1DeviceInfo: FbiConfig:0x2, TmuConfig:0x11
sst1DeviceInfo: FBI Revision:2, TMU Revison:1, Num TMUs:1
sst1DeviceInfo: FBI Memory:2, TMU[0] Memory:2
sst1DeviceInfo: Dac Type: ICS ICS5342
sst1DeviceInfo: SliDetect:0
sst1InitRegisters(): LFB Writes go through memory FIFO...
sst1InitRegisters(): TEXTURE Writes go through memory FIFO...
sst1InitRegisters(): exiting with status 1...
sst1InitShutdown(): Shutting down SST-1 #0...
sst1InitShutdown(): Returning with status 1...

Try something other than Unreal, especially if you are running an original, unpatched version, perhaps it has issues detecting the Voodoo using later drivers.
Try Tomb Raider with the 3Dfx patch under DOS and some other Glide game in Windows.

Ok, it can run Tomb Raider 2 and 3D Mark 99!
So the hardware is ok-ish after the removal of the cap, but the software is ... I will reinstall Windows just to be shure.

I did not know that Unreal had problems with that! Thank you for the info.