Question PC crashes randomly after cleaning dust.

May 24, 2023
Before starting, this is my setup:
MOBO: Gigabyte F2A68HM-H
CPU: AMD A6-7400K
GPU: None.
Adata SU360 480 GB SSD as the main system drive and a Barracuda 2TB HDD for extra storage.

RAM: 8 GB DRR3 1600mHz Kingston Fury
I also use two monitors, an old VGA one and a larger one plugged through HDMI.

The problem:
I cleaned my PC last week. It worked fine for a couple days until it suddenly crashed and making a weird static noise that played through the HDMI screen audio output. I restarted it and it seemed to work fine for a couple hours and then it crashed again.

I tried to clean everything again and this time I changed the thermal paste and cleaned the CPU socket because it had some dust. It worked for a night but then it crashed again.
For the next days i've been trying to use my computer and it halts on different situations. Right during boot, after a couple hours of normal use, sometimes trying to run the windows installer (The first time it worked fine but the second time I booted it halted), and it also crashes on safe mode. Sometimes the PC won't display any image at all and I have to restart it a couple of times. A couple of the crashes had some graphical glitches, like a small and thin horizontal color line or some flickering lines appearing on the sides of the screen.

I've tried memtest86 and surprisingly the computer didn't halted and it finished the test, with no ram errors. (The same happened running windows memory diagnostic, everything seemed to work fine).

The PC crashes randomly regardless if both screens are plugged in or just one (the VGA one).
I also tried to use Prime95 in order to do a cpu stress test but the PC halts every time I start the program and it doesn't seems to record any error.

I tried exploring the Windows Event Viewer but I had no luck since there wasn't anything out of normal.

I don't really know what to do or which part could be the problem.