Newly build computer is not booting

roobinch

Prominent
Dec 15, 2017
1
0
510
I have the following hardware installed:

- AsRock Fatal1ty Z170 Gaming-ITX/ac (LGA 1151, Intel Z170, Mini ITX)
- Intel Core i7 7700 BOX (LGA 1151, 3.60GHz)
- Kingston Value RAM (1x, 16GB, DDR4-2133, DIMM 288)
- Seasonic Platinum 400 Fanless (400W)

I've connected the ATX 12V Power Connector (2x12 pin) and the ATX Power Connector (2x4 pin) to the PSU.

I have also connected the Power Button and the Power LED.

When I now try to boot, all the fans start to spin and the power LED is on. After about 3-5 seconds it turns off and on again. Then it stays on. But it is not booting (I have no output on my HDMI Port)

I have already tested the HDMI cable and monitor (is working, the monitor even turns on when I power on the computer, but no output can be seen).
I've also tested the RAM on both Slots.

Does anyone have another idea what I could try?

Many thanks!