So here is the problem after installing new ram my pc wont open its just black screen ...so my MOBO memory type is 2 x 240pin DDR2 667/ 800MHz support dual channels, max up to 4GB and i bought two 2gb ddr2 memory both are from manufacture HYNIX one ram is 2gb 2RX8 PC2-5300U-555-12 HYMP125U64CP8-Y5 1410 and other is 2GB 2RX8 PC2-5300U-666-10-12 HYMP12564CP8-Y5 AB 1009 ..and if i put both of them pc wont boot and if i put only one ram pc boots up..help please im new to pc world