What to do if the native stick of RAM stops working?

Question

Windows

I ran into a problem after removing and installing RAM. The memory did not change, it remained the same, but at startup the laptop did not start (the cooler is buzzing, the indicators also glow), after I removed one bar (I have 2 x 4GB in total), the system booted up, experimented with places and but the result is the same, it only works with one, I checked it on another computer, it works without problems ... and I also put memory from another laptop in the second slot, everything also works. It turns out that the memory and slots are working, but I didn’t manage to understand what the reason was))

Laptop Acer Aspire E1-572G Windows 10 Enterprise LTSC x 64
1.1 Removed two bars (2 x 4GB) of RAM (during disassembly)
1.2 Put everything back
1.3 When you press the
laptop start button, the indicator lights come on, but the screen is black, nothing else

happens laptop slots
2.2 I realized that with one (let's give it the name X1, the laptop works), on the other (let's give it the name X2) - no. When they stand together, the same result
2.3 I took RAM from another computer, put X1 + X3 - it worked, And X2 - put it on the laptop from which I removed X3 and everything started there too

3.0 Based on everything, I can’t understand what is the reason, if in fact , slots and RAM work, and X1 and X2 worked without problems before

Answer 1

Reset the BIOS to default try for the sake of experiment