Major RAM Problems

[The_Jaeger]

Hello People, i hope you can help, first my System :

Motherboard : Gigabyte G1 Sniper 5 

CPU : Intel Core i7 4790k

RAM: 16GB Corsair Vengeance 2133MHz

GPU : 2x Nvidia Geforce GTX 980

Cooling: Swiftech H220x

Power Supplie: Be Quiet 700W

 

I have got some problems with my RAM, so before i installed my watercooling my PC ran normal with the two RAM Sticks in DIMM 2 and DIMM 4. Then after I installed the watercooling I got a Error Code(15) which stand for : Pre-Memory North-Bridge initialization is started. But the System didn't boot. So i tried to switch Channels with the RAM so a 1 and 3 configuration but this didn't help at all. So i tried to boot with only one Module and the System booted without a problem but the same goes for the second Module, so the modules work without a problem. And then i tried to set one module in Channel 2 and the other in Channel 3 so actually the total wrong way. But the System actually booted and even detected the complet 16GB and the right Frequenzy, but It is still of course running in a single Channel configuration. I have no idea why it doesn't work in a normal Dual Channel Configuration and I dont know how to get them working properly again. I hope maiby anyone of you could help me. Thank you. 

[CoolaxGaming]

Slot 1 and 4 seem dead...

[The_Jaeger]

I tried every single SLOT with one RAM module and yes these slots don't work. But is it possible to fix those or do I have to invest in a new motherboard