[SOLVED] Asus X550VX won't recognize additional ram ?

[Hiro_Boy]

My notebook is ASUS X550VX with 8GB onboard RAM and 1 empty RAM slot of DDR4 2133MHz supports up to 16GB, so I've put Corsair DDR4 2133MHz 16GB in it. here it is.

I checked this question before Ubuntu settings after adding additional RAM and it says there's no need to install anything, Ubuntu will recognize the new ram automaically. However, I've checked in BIOS and also system, here, it only reads my onboard ram (8GB) and not my additional ram (16gb).
I've done sudo apt-get update and rebooted 3 times already but still no luck. Did I miss somehting here ? Why did ASUS won't recognize my additional RAM ?

 

[helpstar]

The Corsair memory is not connected correctly. Insert it in a 35 to 45 degree angle, be sure the gold plated contacts are not visible anymore, then push the memory downwards.

View: https://youtu.be/T7I-7FSn33I?t=322