Question Cant get my second RAM to work.

Oct 2, 2019
6
1
15
I tried to upgrade my RAM from 8gb to 16gb in my prebuilt pc from Lenovo. But when I tried to start the computer after I had installed the second RAM, the pc started to beep. I then tried to start it with just the new RAM inside and the same thing happened. I could only manage to start it when there was Only the old RAM inside.

Both of the sticks are 2666 mhz and from the same brand. Please help.
 

PC Tailor

Illustrious
Ambassador
Welcome to the forums my friend!

Firstly mixed RAM modules are not guaranteed to work together. RAM is only guaranteed in the form sold (from the same pack). Making them the same make/model/timings etc. is just a way to try and minimise risk, but certainly doesn't eliminate it.

Secondly did you also reset CMOS when changing the RAM? You should usually reset BIOS settings so it can reconfigure with the new RAM.

Lastly, following that, you may want to try it in a different RAM slot, if the second module simply doesn't work at all, it is probably DOA and should be returned.
 

PC Tailor

Illustrious
Ambassador
You either reset the BIOS to defaults or remove the motherboard CMOS battery if you are able to access it. Not always so simple of laptops.

Also, they both have the same module number: RMUA5110ME78HAF-2666
Irrelevant unfortunately. Being the same model are still mixed RAM modules. I'll quote the explanation of this from another post I made elsewhere:
The manufacturing of RAM (and almost any PCB or chip) is actually a very delicate process, it is performed in very highly regulated clean rooms, and the material that goes into those components are also very delicate to change.

Each chip is cut out of silicon, and that silicon can be prone to various impurities or contamination even simply from dust, which can affect the compatibility of the modules. The point being, is they pre-determine the modules that will go in a pack, manufacture accordingly, and then test them on a system together at the end, so by all accounts, there are no guarantees thereafter.

You can actually buy 2 of the EXACT SAME MODEL RAM, but from 2 different packs, and they can (and have) not be compatible.

So does it not work all of the time? No, there are plenty of times where it does work.
But is it a gamble? Absolutely yes.
 
  • Like
Reactions: Phaaze88

PC Tailor

Illustrious
Ambassador
Oh I guess I was just unlucky. Should I return it and instead by a pack of two 8gb? And if so, which ones do you recommend?
Well first I would try the working RAM stick in each slot and verify it's the module that is faulty and not the slot. If the old RAM stick (that you know works) doesn't work at all in the second slot, you know it's potentially the slot.

If you do find it's just the new RAM module is DOA, then you can always try returning it and trying with the new one, just it could be a gamble again.

I personally would advise just using Crucial's memory picker, as long as you stick to the same spec that your laptop supports, you should be fine.