Hi. I think I can relate to your issue,
I will usually take out ram, spray contact cleaner on slots and ram, wait and cool it off, reseat ram, test again if it boots up then do memtest.
My current PC(and a previous pc) that i am using has this habit to hang once in a blue moon. If i try to turn it on without doing a cold boot, it will just power up without any screen(no beep sound). So i have to cut off the power first and wait for a while. Once i managed to get it to boot past splash screen, it will definately show cmos checksum error and goes back to default(sometimes it retains my bios settings, which is lol even though it says the bios has been resetted to default)
Cmos batt isn't out of charge. Memtest doesn't show any issues after 10cycles. I even tested on a different power supply from my gaming pc. Same issue so i narrowed down to mobo issue or ram, since this has happened before on a previous pc, i started to check on the ram first because my previous one had this same weird issue.. it's like as if the ram slots somehow lost contact with the ram connectors. I am never a fan of the standard ram slot designs tbh, prefer the 'clip in from the side' laptop ram slots. As for mobo.. took out rams and booted pc, mobo seems fine with the error beep sounds.
Also, another observation about these standard ram slots is that there is a chance that it will not boot up if you shake the ram slightly(when turned off of course) while already properly slotted into. This usually happens to me on aging systems. Hence the reason for using contact cleaners.. Anyone else experienced this before?
Note that both my PCs having this issue are still working fine now..



I have a new gaming rig that doesn't have this problem(yet)
God forbid......