Upgrade memory laptop

[Kalmah89]

Hello there. I bought these days a 4GB memory from kingston, for my laptop Asus X552LDV. The laptop specs allows me to upgrade from 4 to 8 GB ram. I bought the same ram: DDR3, 1600 Mhz, 1.5 V. But the laptop dont recognize the ram. What can be the problem? Sorry for my language.

 

[ak47jar3d]

Mixing and matching ram cards is a bad idea. I would get 2x 4gb as ram cards are meant to be bought as a set.

http://www.datamemorysystems.com/dm50-233-1l/

 

[Kalmah89]

why is a bad idea? and why should i get a set if the laptop has already 4 gb, and the other memory is exactly as the other as specs.

 

[Kalmah89]

think i found the problem. i need a 1.35 V memory ram, according wwith my processor type: i5-4210U. it is correct?