Latitude C610

Please tell me, I bought a new memory for my old dell Latitude. The same specification from the presently installed one. I bought 1pc of 512mb memory the same everything of the old installed one. I installed 1 oled memory that is 128 MB and I installed the the new one 512 MB. But sad to say the memory could not be read by my laptop. Please help anybody?

Anyone have got the solution? It's long time, Would you pls post it here? Thank you!