Can you look on the bottom of the case, is there a small hole there? If so, remove the power lead from the device, find a thin paper clip (if it is the one I'm thinking of, I needed to strip some plastic off the end of a twist/bag tie
as my paper clips and standard poking objects were too wide.
Push it in straight, and you should feel the resistance change slightly as a hidden switch is pressed down. Keep it in that position and reattach the power lead. If the device doesn't turn on automatically, use the infrared remote control to power it up. After about 10-20 seconds, the Recovery Menu should appear, you can release the hidden switch then.
From this point, follow the steps at
to carry out a factory reset (all data will be wiped).
First boot up after that, once you see the normal homescreen, leave it alone a good 15/20 minutes please, don't power off.
https://droidbox.co.uk/how-to/what-is-the-recovery-menu/ goes into more detail about the Recovery Menu itself.
If that doesn't help, email DroidBOX with the info mentioned in my signature link.