What the beep codes signify depends on the brand/type of motherboard BIOS. For example, on Dell desktop systems, 8 beeps usually means the CPU is goosed; on other systems, it can mean the graphics card memory has failed.
Start with removing the graphics card and starting the PC up: you should get a different error beep this time, reporting that there is no video adapter present (unless the CPU has an integrated graphics chip). If it is a different beep code, then the card has failed.