Question RAM Upgrade Mystery: Legion Y520 Won't Boot Without Specific Module

[somecoolusernameimusing]

Hello. I wanted to upgrade my RAM on my Lenovo Legion Y520-15ikbn, but I discovered some strange behavior of my current RAM modules.
I have 2 modules - 2gb and 4gb one. They are Ramaxel Rmsa3270mb76h8f-2400 and Rmsa3270mb86h9f-2400 respectively.
I cant launch my laptop without 2gb module in it's slot. If I swap my modules, or put only 4gb in slot from 2gb my machine won't start.
Also my system doesn't see Patriot ddr4-2400 8GB PSD48G240081S module I bought, despite a slot it's installed.

---

I can guess that Ramaxel and Patriot modules doesn't fit together, but it's a mystery for my why I need 2gb module to start the system.
I couldn't find the information I needed on the Internet, but I hope knowledgeable people here can help me.

 

[Ralston18]

Multiple potential problems.....

Update your post to include full system hardware specs and OS information.

Motherboard: Go to the motherboard's manufacturer's web site and find the applicable User Guide/Manual.

Check that the installed RAM is both supported and installed in a supported configuration. Look for updates on the website.

Some motherboards also require that the first phyically installed RAM be places in a specific slot.

Note: Do be sure that you are truly at the motherboard manufacturer's website. Just because the manufacturer's name appears in the URL that does not necessarily mean that the website is the actual manufacturer's website.