[HELP][MacBook Pro, early 2008] RAM Upgrade Issues

My early 2008 15" MacBook Pro (one before the unibody version) came with 2x 1GB RAM modules.

I ordered the same DDR2 667 (PC2) PNY RAM upgrade kit (2x 2GB).

When I removed the stock and inserted the new RAM modules, the system powers on, but I do not get any display nor does the system actually boot up.

I tried having one stock RAM module (old 1GB) and new one (new 2GB), so the new 3GB combination works. I know for a fact that 4gb is supported according to Apple documentation.

I want to be able to run on 4gb RAM and not 3gb, If anyone has any answers to this please help