The memory is not compatible. 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. 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. 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 slot is dusty or oxidized. Você pode usar o saldo total do crédito. 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. Instruction:The memory module is divided into SD, DDR, DDR2, DDR3 models. asrock n68c-s ucc manual.