Ojdå, såg inte att det var en laptop, dåligt läst av mig. -.-'
Googlade runt lite och det är endel folk med samma problem testa att göra detta:
Laptops can be VERY picky on memory module.
(1) Did you first verify that the Memory is on the "Compataility" list
(2) Did you match the Voltage rating and CL ratings, For laptops, I've found that matching the specs (excluding size) is a good idea.
You indicated that your laptop will not power on after you re-installed the orignal memory. Two Posibilities:
(1) the Bios tried to change it's settings to match the New ram and has retained the settings - Which no longer match your orignal memory. If this is the case then you need to findout how to reset the Bios to "factory" settings.
(2) Always a possibility - You may have: (a) not fully inserted the Ram, or (b) you damaged the a memory module or a component on the MB. Try One stick of memory at a time to see if you can get the laptop to power on.
Remember - Memory Modules and the area around the socket on the MB are ESD sensitive.