Excuse the blurry picture, but this shit makes me angry.

Both this sticks has the same modelnumber/productnumber, but the tiny text to the right is important to! I cant find any information regarding thoose sticks about there is actually two version of them! $150 down the drain. Fuck it

That system specyfic ram for ya!
(its usualy more expensive than normal one)

I hope you can return them easliy.

On Samsung sticks, I thought those numbers were time codes YYWW. One was made in week 44 of 2014, the other in week 29 of the same year. Let me know if it stands for something else. What's the issue you're having?

@cmplxcarlo maybe the chips are made in another country but the sticks are manufactured in ph?

On modern systems you can usually use any combination of sticks and probably still run them in dual channel. Are you sure you don't just have a bent/broken pin somewhere?

@Linux i have 12 sticks like the one in the picture lying around... if they are useful to you we could talk about a sell or trade =)

@Byomeer
Thanks! But thoose does not work for me :) different memory

Hmmm Well... PC3L tells me that these are low voltage DDR3 modules.
Not all Mainboards can handle that ...

Can't read the rest of the stickers :-/ sorry

So my point was, running those in a laptop will might be fine. Most likely.
But as these looks like DIMM modules i asume you put those in your desktop.

Running Low.Voltage modules with normal voltage modules combined will not work.
So if there are more modules installed, check the types of those.

@Rohr
Thoose are not for laptop but full side DDR3 ECC sticks, the one in the bottom works.

@Linux sorry then... thought i could sweeten your day, failed hard instead =D

@Byomeer
😘😘😘😘

I thought that is used to know the pair from a set of ram

@devTea
So what kind of ram would you buy in this case?

@Linux I mean when I buy 2x8GB RAM, if you bought each of them sepparately the only thing I need to check is that 12800 number

EDIT: I have also mixed those pair when my company was installing an internet cafe with a lot of computer and a lot of double RAM

@devTea
Check the modelnumber and look, both is PC12800.

What mobo and cpu are you using? Did you try the new stick alone and in other slots?