Computer Does't Work At Maximum RAM

[jebondoc]

I have a Sony VAIO model VPCEA21FD. In the specifications it states that the maximum RAM is for this unit is 8GB (DDR3 1066Mhz - PC8500). Preinstalled it came with 4GB (2x 2GB), I recently bought 8 GB of RAM (2x 4GB PNY DDR3 1066 Mhz) and proceeded to install the RAM in the slots provided. When I started the computer my laptop would not boot up to windows, just a black screen and then I heard the fan kick up and then my computer turned off by itself. Later I installed 6GB of RAM (installed one of the new ram and one of my old ram) At this configuration, my computer booted up and proceeded to work as normal, checked the system and I was able to view 6GB of RAM in my computer it was being read by my laptop. Question - How can I get all 8 GB of RAM to work in my laptop?? Please help if you can.

 

[Vic 40]

If it works with one of the 4gb sticks can you try to set the bios to the right speed/latency's and voltage with it,then adding the second stick to test.

 

[spooky2th]

I would try one 4GB stick in each slot and then the other if the first stick didn't work. If you can get one to work, boot into bios and set up the timing and speed and then try both together. When ever you change RAM you will have to go into bios and set it up. RAM unfortunately is not plug&play.