Question occuping 4th ram slot on motherboard causes pc not to post


Feb 9, 2016
I bought a new NZXT H500i case couple of days ago and had to transfer my hardware to it, i did and it all was working fine until a day ago when my PC randomly frooze and every USB stopped getting power. I turned off my PC and booted it again, but it won't post anything. the fans we're spinning RGB lights were on but the keyboard,mouse & display wouldn't turn on.
I took the power cord out and draining the remaining power in the hardware then it turned on. I thought it was a one time weird thing.
but now while playing csgo it happened again. i tried to do the same thing and it worked but then the pc froze again after 20 seconds and after that i couldn't get it to boot again.
I googled some and started taking out some component, first tried to remove the GPU and boot the pc using the iGpu didnt help.
Then i took 3 of the ram sticks and booted it with one and it worked.
then i started putted the ram back 1 by 1 and when using all of the ram slots the pc wont boot. i checked if it was the particular stick but it wasn't its like when using the 4th slot the motherboard just won't post.
do i RMA or there's something i can try doing about it?

Thanks in advance.