[SOLVED] PC runs for a few seconds, doesn't boot, shuts down, and repeats this

[facusml16]

Context: Today I used my PC for just an hour, because my brother was annoying me to let him play, did so, just went to my room and left my PC to his care, he didn't shut down the PC or anything, just left it there, went for a shower and came back, played for a bit but suddenly the headsets were making a weird noise like a beep (endless), and the PC just crashed.
He then proceeded to restart it, but it wasn't booting, so he came and asked me to fix it, the PC had a similar problem months ago, where I solved it by removing the mobo's battery and setting it back on again after some minutes, which solved this for me in that time.
This time around however, didn't work, fans run and all but there's no display, PC doesn't boot completely, and it just runs on for a few second (maybe 10) and shuts down automatically, after 5 secondw starts by itself again and shuts down after 10 seconds, it's a loop I can't seem to get out of.
Have tried reseating RAM sticks, didn't work, tried removing GPU, didn't work, tried reconnecting some of the wires (not all, I have a headache rn and didn't want to lose too much time while also breaking my back), didn't work but will try to reseat everything tomorrow in the morning, hopefully it does fix but anyway... Do you guys have any helpful info that may help me solve this problem? Also, for some extra context, tried reseating mobo battery 3 times already, where everytime I removed it, left it for a few minutes til I could put it back in.
Hardware:
GPU RX560
CPU i3-6100
PSU CX-450 (the silver one)
RAM Patriot 4GBx2 2133MHz
Storage WD-7200 320GB
Mobo GIGABYTE H110MA

 

[Lutfij]

Looks like either a grounding issue or your PSU is failing. Might want to see if the system boots up with the discrete GPU removed and then with the discrete introduced but breadboarded.

 

[facusml16]

Looks like either a grounding issue or your PSU is failing. Might want to see if the system boots up with the discrete GPU removed and then with the discrete introduced but breadboarded.

I had my GPU removed by then, today I tried clearing CMOS again and unplugged everything, left the battery for 20m, came back, put the battery back in and reseated everything, and it turned on, tried with the GPU and it worked just fine, but, while I was in a call and playing, my screen suddenly froze and I couldn't move anything, but my system was still running, however I noticed that the red led of the case (I believe it activates since the computer boots) wasn't on, only the blue led was on (activates when the pc is receiving power, I think). I decided to restart my system after waiting for 10m (forgot to mention, my screen froze almost 30m after I turned on the pc) and it didn't do much, it got into the same loop of my pc trying to restart, but no being able to, only blue led turned on

 

[facusml16]

Nevermind, somehow solved it, unplugged everything (even CPU cooler and CPU), cleanes the dust, reseated everything back and it somehow works since a few days ago... I don't know what it could've been but well, I had luck it wasn't anything worse.