I bought a motherboard off the net for my P4 CPU. This board uses DDR2 ram memory. I bought a 2g stick of DDR2 ram made by Kingston. After I installed the memory I started up the unit and it didn't boot up. The lights on the board goes on, however the bios doesn't come up. I talked to the web site that sold the board and they said the memory was most likely not compatible. The web site said that Kingston ram is junk. I tried a Samsung DDR2 stick and it still didn't boot up.
Have you tried placing the RAM in the other slots to see if it boots. I'm concerned that you have tried two different RAM sets and have the same issues. You might have a DOA motherboard. Can you try the RAM in another PC to verify the RAM is good?