Question Power Outage + RAM mystery

May 26, 2020

ill start with pc specs:
MOBO: Gigabyte B450M DS3H
CPU: AMD Ryzen 5 3600 with stock cooler
RAM: G.SKILL Ripjaws V 16GB (2x8GB) DDR4-3200MHz CL16
GPU: Gigabyte GeForce GTX 1650 SUPER Windforce 4GB OC
SSD: M.2 2280 Western Digital Blue 1TB 3D NAND SATA
PSU: Nox Urano VX 650W 80 PLUS Bronze Edition

Recently my 2 months old faced some problems with a power outage. The fans and motherboard lightings would go on but both monitors wouldn't receive any signal from the computer so, the BIOS wasn't POSTing.

After some research, I started trying out stuff like shut the power completly from the computer for 10 minutes, trying to press 15sec in power button once it has booted... And none of the previous worked so next thing i did was to test if the RAMS were ok.

I adopted the single RAM test. I started from unplugging the 2nd DIMM and right away the PC booted. Right after that i removed the previous tested RAM and plugged the other one "main" slot it was also ok. However, when I would plug both of them the PC wouldn´t POST again. So, I wanted to get out of the way the XMP Profile would somehow be causing the problem leaving the motherboard as fabric default to the respect of memory "overclocking".

So, i had to boot again with one DIMM and disabled the XMP profile in the BIOS. Then, i plugged the back the 2nd DIMM et voilat... PC booted with both RAM sticks but at deafult speed. So i did went to the BIOS again to try to activate the XMP profile and PC started working properly.

So, to the matter of scientific observation i got one more power outage since then and "simulated" other one by just toggling the power suply switch to 0. And in the both circunstances the PC behaved the same way with the same way fixing.

What might be causing this ? I mean, i just wanted to know in the sake of curiosity what is happening because it's boring and somehow risky to plug/unplug the RAMs every time PC goes out of power (wich fortunately isn't very often)