The problem is already solved.

[konstantinhaferl]

Solved. Solved. Solved. Solved. Solved. Solved.

 

[keatingscool]

Please list the specs of your motherboard, RAM, and CPU.

 

[konstantinhaferl]

MB is the Gigabyte z97x-sli
CPU is the i5-4590
Ram: Hyper X fury 1333mhz,
One 2×4 kit and two single 4gb

 

[keatingscool]

Well it looks like everything should be compatible with eachother.

So, next thing we have to do is diagnose what could be wrong. Have you tried moving the previos ram that wroked in the other slots you installed RAM. Maybe the other RAM slots are bad?

Keep switching out RAM on different slots to see and diagnose if RAM could be bad or the SLOTS.

 

[geofelt]

Your ram is not identical.

Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboardscan be very sensitive to this.
This is more difficult when more sticks are involved.
That is why ram vendors will NOT support ram that is not bought in one kit.
It is safer to get what you need in one kit.
But, it is a bit more expensive because of the added matching of all the sticks to insure compatibility.

First of all, test each stick individually with memtest86 to verify that they are good.

You might get all to work by entering the bios using your original 2 sticks and upping the ram voltage a bit.
Then install the extra two sticks.

If all else fails, buy a compatible 2 x 8gb kit and market your old sticks.