I have an ASRock G31M-S (Bios Version P2.10), currently it is with a Core 2 Quad 9550 and a GTX 750TI. 1x 2GB DDR2 and 1x 4GB DDR2 (Total 6GB). I had a problem with this motherboard that stopped video, the card was turned on, the coolers were running, but no video came out). I bought another one and the memory card of Markvision 4GB DDR2 800Mhz is no longer being recognized, I'm sure it is not broken because I tested it on another motherboard and it worked, but when I put it on the ASRock G31M-S, it is without video and there is no beep in BIOS.
Can it be some BIOS setup? The memorys cards have the same bus. Honestly I'm scared to have lost this 4GB DDR2 memory so hard to find.