The device hangs on the "Mbox" or "Google TV" splash screen.
Run the Rockchip Driver Assistant on your PC and click "Install." Firmware Rk3128 Mxq Ep 68
The software used to push the firmware image (.img) to the box. 4. How to Flash the Firmware The device hangs on the "Mbox" or "Google TV" splash screen
Needed to connect the box to your computer. Firmware Rk3128 Mxq Ep 68
This usually indicates a firmware mismatch. Double-check that your board is indeed an EP-68 and not a V88 or an Amlogic-based MXQ.
Guide to Firmware RK3128 MXQ EP-68: Identification and Installation
Try a different USB port on your PC (preferably a 2.0 port) or a different USB cable.