The memory slot is dusty or oxidized. Use a brush and wash water to clean it (if you don't have wash water, just brush it down)c. asrock n68c-s ucc manual. . It is not allowed to install a DDR3 memory module into DDR2 slot or install a DDR2 memory module into DDR3 slot; otherwise, this motherboard and DIMM may be. The memory is not compatible. Instruction:The memory module is divided into SD, DDR, DDR2, DDR3 models. Channel. This motherboard provides two pin DDR2 (Double Data Rate 2) DIMM slots and two pin DDR3 (Double Data Rate 3) DIMM slots, and supports Dual. This motherboard provides two pin DDR2 (Double Data Rate 2) DIMM slots and two pin DDR3 (Double Data Rate 3) DIMM slots, and supports Dual Channel. Você pode usar o saldo total do crédito. The memory slot is dusty or oxidized.