Gigabyte H77 DualBios BOOT-LOOP

[Onyxacek]

Hello there,
so I've got kinda strange problem. I'm about to sell my computer to a friend, I have put everything out of the case, cleaned everything, and then I connected everything in ghetto test-bench style on motherboard box. And since then I'm stuck. I have i5-3470 and 16 Gb of RAM - but it's triple channel. It's weird I know, but strangely enough I have 2x4 Gb DDR3 HyperX Genesis and I won in a competition 1x8Gb DDR3 HyperX Fury Blue. It worked for 6 months and now, I can't get it to boot. All of RAM modules are functional, since I'm able to boot with single stick .. either 4 or 8, but I can't boot with all of them. I'm running out of ideas, could anyone please help me ?
Thanks a lot.

Things I tried:
Clearing CMOS via shortage and battery remove - no effect
Swapping all of sticks.. alone they works .. but even 2x4 kit combo doesn't work properly.
Trying to get into recovery.. it fails when I use more than 1 stick

 

[Onyxacek]

Nevermind, where I can find a solution, it doesn't work, and if there is problem same as mine.. nobody answers. Great.
I've visited the most educated person at my IT school and asked him about the situation. He said, that it might be something with unsupported channels. But swapping RAMs all over the place didn't help. If anyone finds himself in same situation as me.. good luck. I'll stick with one working stick and sell others.