Question DIMM 2 works only sometimes.

Jul 28, 2020
So basically I got a mid budget setup (it is mid budget where I'm from) for my younger brother, so when I was at shop everything was working perfectly fine, and packed it up and shipped it ( it was already assembled).

When my brother got the PC the GPU was out of slot and was in just left inside the casing (no harm was done to it and it was screwed), after placing it, it wasn't showing display, and usual troubleshooting began and turned out when sitck was removed from DIMM2 , PC starting working, then after trying combination and trying out sticks 1 by 1, it eventually worked and was working perfectly fine till yesterday (was bought last Wednesday), then it restarted and was showing no display, then we tried to loosen up the cooler and it worked. Then after that it crashed and similar things happened and we tried to loosen up again but this time it didn't work. Was in same situation myself few months ago with my PC, and retailer to me sometimes because of cooler being tight the CPU doesn't recognize/work with few ram slots, I'm just here to confirm the theory and if that theory is true then what would be the solution, can't ship it back and can't get new cooler cause of lockdown and yeah both sticks are fine.

Generic Intel Mobo
i5 3rd gen
8GB(2x4) same frequency and make
RX570 4GB
PSU 650w Corsair.

Any help would be appreciated.
Sorry for the long post, actually this is the first time im asking for help on any forum cause usually i try to find the solution myself but this time the PC is in a different city and my brother isn't good with PC.

Thank you.