The laptop does not see the RAM, what's the problem?

Question

laptops

In short, we decided to put another RAM on the lenovo g50-30 laptop, instead of the native one (2gb). There is only 1 slot, so we bought a 4gb RAM, but after inserting it, it turned on, but the screen did not show (the cooler started working, but the screen was black), we tried 4 different RAMs from different manufacturers and frequencies (we had it at 1600, we also set at 1600 and at 1333, there is also no result). Can you suggest what is the problem?

Answer 1

Does it work at home after that?
Update bios, try.

Answer 2

What kind of memory was, what kind of set? Accurate labeling required. The voltage may vary, for example.
After all these manipulations with the old one, does it start? Or maybe the legs of the slot are damaged?