Quadro K620 in Dell Vostro 260

If no discrete gpu detected at all under dev mgr, and only Intel integrated graphics shows up there, it means the card is not detected by bios.

@redxps630​ so it isn't fixable?

Try replace cmos battery of V260 and clear CMOs settings via motherboard jumper. If this legacy model CMOs is corrupted it may fail to detect an otherwise working gpu.

You need to check the serial number on that quadro K620. That is a work station card and it means it potentially has w VBIOS lock for the specific pre built manufacturer. Meaning if it came from HP, or Lenovo, it wont work on your dell. It has to be a dell pre built K620 with dells service serial number sku, or it needs to be a PNY, or Nvidia that doesn't have the serial number service sku. 

 Its hard to look up the seria sku for what pre built it comes from so I usually rely on ebay. Where the vendors are more familiar with the serial numbers and identifying.

Also a K620 is poop. Its feature set wont allow you to game or do any serious rendering with modern programs. You can do minimal 3d print schematics with it but nothing major. If you need a card that offers the best value and range for basic needs look into the nvidia quadro M2000 (which is basically a GTX1050) you can get on ebay for under $35.

Its the best card for the value as it will do all old school retro gaming, and modern gaming as it uses feature set DX12 and was the first generation to use nvidia CUDA.

@PC Parts Bin​ The model I bought was a PNY, but it still isn't working.

Hi,   So what you need is a new CMOs battery.

After CMOs battery replacement

go into BIOs as everything will be reset.

Take the card out and you will have to set up your bios from the jntegrated graphics of the CPU first.

-go to security, turn secure boot off.

-go to video, select automatic or video card

-If your bios has the option turn fast boot off

-Boot turn UEFI on but make sure Legay boot is supported. The K620 is now considered a legacy card to the operating system if you have windows 10 to windows 11.

If you have done everything I have stated. It might be your monitor isnt posting. Quadro Cards are highly sensitive to theDP/HDMI generation that is supported. Most LED TV’s that do not have whats called “generic Pnp” monitor driver sets will just give a black screen.

try to use a Display monitor no higher than 1080P that offersDVI/DP/VGA input.