PC won't turn on (4 beeps) when 4Gb ram is inserted.

[FranBlagru]

My PC won't turn on when 4gb of 6gb is inserted. With the 2gb it works, and another thing is that it doesn't output the display from the GPU but it outputs it from the motherboard instead, for some reason, and the GPU fan works, but no output comes out.
GPU: Nvidia GeForce GT520
RAM: 4GB + 2GB (6GB)
Thanks in advance.

 

[LightningsalesUK]

it could that the ram is faulty, check all the little gold resistors, it could be one of those.

 

[FranBlagru]

Yea the ram might be faulty, but the graphics card? The fan on the graphics card works, but it doesn't output anything.

 

[Tradesman1]

Guessing in the BIOS your primary video is set to on-board when it needs to be on PCI-E or PEG, on the DRAM need to know the model numbers of the DRAM as well as what CPU and mobo