i have built a pc and am having a major problem. the first few time it booted it was fine, windows loaded and was working.i turned it off to install the network card but then for an unknown reason it has stopped working. now when it boots up i get no video signal and 3 beeps. the beeps are the same tone and legth and are evenly spaced. the sounds keeps repeating after a few seconds. i read that it could be the memory so i changed it. the beeps have stopped but still no video. it's a brand new video card but slightly used mother board. the motherboard is a soltek top mainboard. and the graphics card is a sapphire. any help would be greatly appreciated. could it be the motherboard?