I just bought the new Acer Aspire AS5250-BZ853 along with the 4 GB RAM stick to upgrade (it only came with 2GB and reviews said 4GB definitely worked better). Before I even turned it on for the first time I opened the back and slid the 4GB RAM stick into the little pocket over the 2GB already in. It didn't come with a manual and I was unable to find one online but maximum Ram is 8GB. When I put the back back on, put the battery in, plugged it into power, and pushed the power button the computer wouldn't run properly. It would turn on but keep running and not do anything, nothing would ever come up on the screen. I took the 4GB back out, put everything back together, turned it on with the 2GB that was already in before and everything worked fine. I tried putting the 4GB back in and it still did the same thing... What's going on!? I would really appreciate any help on this