In certain cases, a Mastermind GT will get into a state that makes it impossible to factory reset it or load new settings from the computer. This is a process you can use to get your GT up and running again.
You will need a FAT (PC) formatted flash drive for this process. The one that was included with the GT will work. If you buy a flash drive, it should be 32GB or less in size, and USB 2.0. 64GB or larger drives will definitely not work. USB 3.0 drives may work, but there's no guarantee.
- Plug the flash drive into your computer
 - Remove all files that end in .rjf from your flash drive
 - Download the MMGTUtil01.rjf file from the link at the bottom of this page
 - Copy the file to the flash drive
 - Eject the drive from your computer
 - Power up your GT while holding the two black buttons under the main screen
 - Plug the flash drive into the GT
 - It should load from the flash drive, then go into "Mastermind GT Utility"
 - It will now erase all of your settings on the GT. This takes about 2 or 3 minutes, and it will put a message on the screen telling you when it's done
 - When it's done, power down the GT
 - Plug the flash drive into your computer
 - Remove all files that end in .rjf from your flash drive
 - Copy the latest GT firmware file to the flash drive. If the file is a ZIP file, double click to unzip it, then copy the RJF file to the flash drive.
 - Eject the drive from your computer
 - Power up your GT while holding the two black buttons under the main screen
 - Plug the flash drive into the GT
 - It should load from the flash drive, then perform a factory reset.
 
At this point, it should be working normally once again. If it isn't, please start a support ticket and we'll help you out.