Added a new ram, now has green lines across screen

[Mario_713]

I have an inspiron n5040 and tried adding a "4gb 1rx8 pc3l-12800s-11-12-b4 samsung" to the second slot. Once I added it and turned on the computer the screen would load up and then once it would get to the starting windows screen it would either just freeze before the symbol popped up or the symbol would pop up but the screen would then have green lines up and down the screen and stop working. If i take out the ram that i added the laptop still turns on and works.

 

[Aeacus]

Your new RAM isn't compatible with your laptop, that's why it doesn't work.

For compatible RAM, i suggest you pick one from the Crucial website,
link: http://www.crucial.com/usa/en/compatible-upgrade-for/Dell/inspiron-15-(n5040)#memoryResults

Either go with single stick or buy matching set. Matching set would be better since it's confirmed by Crucial that those two RAM sticks do work together in that laptop.