Verify that you have the correct memory module for your system. 

The new memory module(s) may not be compatible with your system. The newer memory modules are being manufactured with high density IC’s (little black chips). They now come with 8 (on one side), 4 (on each side) or 8 (on each side). The design inside of the IC’s on the Memory Modules may be too complex for your system to read and it may not work in your system. 

Make sure that the memory is seated properly in the computer socket with both clips locking on their own. 

Verify that the addition of the module does not exceed the memory capacity of your computer. 

Test each module in the system to see which is defective by performing the following procedure for each memory module: 

A: Shut down your system

B: Remove all the memory modules from your system. 

C: Insert one memory module at a time and boot the system up to ensure its compatibility

D: After each module is successfully tested insert all modules into the system and boot up. 

NOTE: Place the highest memory module closest to the processor and work down. 

If you have identified a defective module, return the memory module to the retailer (vendor) where you purchased it for an exchange. If the exchange Period has expired, then contact PNY to obtain a Returned Merchandise Authorization (RMA) number to return the memory directly to PNY's Service center for warranty service/replacement.