Question Windows would not start after change of RAM

Sep 4, 2019

I have a custum made pc which I have assembled 4 month ago. I had before some troubles with RAM sticks and that my PC would not boot ( which is followed by my screen showing me that there is no connection and screen turns off ). I figured it out somehow and left 2 x 8gb RAM. Yesterday I realized that it is not enough for my needs and decided to buy a new kit instead of the old one. After couple of minutes of hell of installation process of the new RAM I managed to get it booted. I managed to open bios and see that everything is in order - it indeed sees both of my 2x32 gb RAM although overal MHz seems to be lower than I expected ( RAM is supposed to be 3200 MHz, but bios shows me that in summary it operates at 2100-ish). Well, it is as it is. I relaunched PC and for some reason I just dont go past the loading screen where you can press button to get to bios, as soon as it tries to load windows - my screen goes: no connection, and turns off (pc still working, its just the screen that gave up ). And I am not sure what to fo about it, this similar situation happened before with old RAM that I had when I tried to install 2 separate kits (same manufacturer, model but just different kits) it just would not work with 4 of them at once, at best I could achieve 3. So i left just one kit and it worked. But now I also have one kit, but it just wouldnt work.
Update: I swapped one stick with another in their spots ( forgot to mention that I used 2nd and 4th slot) and... it worked! Or I thought so. It launched, everything was beautifully working, and I decided to put it into test - I launched a render in Blender and it crashed ( the reason I thought I needed better RAM) after that, the same problem returned. Than after relaunching my pc for about 20 times - it was alright again! Then I was working on something else, not entirely RAM requiring, it died on me again and doesn't really want to work again. I love working with RAM.

Here are my specs:
CPU: Ryzen 2700x
Motherboard: MSI 470x Gaming pro
GPU: 2 x Radeon 580x
System: Win 10 64x
Power unit: Evga 750GQ

Former RAM: DDR4 2x8 gb HyperX Fury 2666 Mhz CL 16
New RAM: Open-box System Memory Corsair 2x32gb kit DDR4 3200MHz CL16 Vengence LPX.

Thank you.