USED 4GB Nvidia QUADRO K5000 Graphics Video Card 4 MAC Pro Computer PC PNY GDDR5

Still not sure if the video card is the source of the problem or not. Basically on startup my mac pro screen goes black and starts having the white light in the lower right corner blink three times.

Could be a memory problem? The guy i bought it from said it would work, but it did not work for me on fixing the booting problem with my Mac Pro. Yes it is good condition, previously taken out of a desktop that was working optimally. My suggestion would be to download and install the suggested drivers through the nvidia website. This will allow your computer and the GPU to interact successfully. This item is in the category "Computers/Tablets & Networking\Computer Components & Parts\Graphics/Video Cards". The seller is "adawg" and is located in this country: US.

This item can be shipped to United States, Canada, Bermuda.

Memory Size: 4 GB
Connectors: DisplayPort, DVI, DVI-I
Chipset/GPU Manufacturer: NVIDIA
Memory Type: GDDR5
UPC: 0751492544236
Brand: PNY
Chipset Manufacturer: NVIDIA
MPN: VCQK5000-PB
Chipset/GPU Model: NVIDIA Quadro K5000