Laptop Restarting After Installing New RAM?

Question

I have a Toshiba Satellite A105-S2061 laptop that has 2 slots for RAM. Each slot can take a gig each, so 2 gigs total. The laptop came with 2 256MB sticks, and I replaced one with a 1GB late last year. Today I tried to replace the remaining 256MB stick, but ran into some issues.

For some reason when I have both of the sticks of RAM installed, the computer powers up then restarts (as if someone was holding down the power button) without any screen popping up. Now when I have either gig stick installed with the old 256MB one, it works fine. But with both gig sticks it does that, it it happens about 7 times before it just stays powered off. What is the problem here?

The new 1GB Ram i purchased is DDR2 PC2-5300, and compatible with PC2-4200, as well as the older one. The new one is PNY, the other is some other company. They both have a 16 x 64mb chip count. Any help is much appreciated.

Answer 1

You can not mix and match RAM module speeds. They must be the same in speed.  

Answer 2

My first guess is dual-channel problem, if the 2 slots does run dual-channel, having 2x1GB will force the board to run in dual-channel, even though they may be similar in specs, a slight timing different or speed can cause the dual-channel to fail causing the machine to reset