Hi, I am building a new rig and really need some help. I am just trying to test the system and i cant make it show up on the monitor

Motherboard- GIGABYTE 990FXA-UD3
CPU- AMD ATHLON II
RAM-NANYA 2GB x 2
PSU- Corsair HX850i

OS- ETHos boot from USB

tried both
GPU- MSI AMD rx 570
GIGABYTE AMD rx 560

keyboard and mouse are USB monitor is a DELL, plugged into DVI

all of the fans power on, usb for OS is warm, light is on for ethernet cable

I have tried: changing the slots for the RAM and GPU and tried a different USB with the ETHos on it in each 3.0 slot and the slots under the ethernet cable.

Please help! and thank you for any help anyone can give