I am not familiar with the Mini either.
But since it is almost the same as a 150, have you tried checking the power supply.
If it is a 9v 3-prong power supply, probably just change it out.
If it is a 8v 2-prong power supply, check it out.
Have them unplug it for about 10-15 min then plug it in and watch the lights.

If NO lights - change the P/S.
If lights seem to start and then never finish - may want to change the power supply to see if that fixes it.
If it boots up and then later quits- change the power supply.

Other than that, connect a laptop to the serial port and see what it says.


If CON is the opposite of PRO
Then what is the opposite of Progress?