Laptop memory does not see 8 GB

[brublag]

I have a Compaq CQ57 and the specs say that it can handle up to 8 GB of memory but when I install 8 GB using two 4 GB memory sticks or one 4 GB stick it will not boot. The two 2 GB memory sticks that are being used in the CQ57 will work in a Dell E6510 that I have. Specs say that the memory should be DDR3 1333MHz which is the same for the Dell E6510. Any advice or solutions are greatly appreciated.

 

[brublag]

They are the same speed but I don't know about the cas latency. How do I find that?

 

[brublag]

The are both DDR3 1333 MHz.