For reasons such as clearing custom work, recovering from a teal-screen, or replacing with a new-in-box tablet, you may wish to reset the Trofa's Nexus tablet to a factory generic image.
From this version, it can be connected to Wi-Fi and updated by our support team to a working image.
Small pliers, wrench, or nut driver to remove 7mm nuts; microUSB cable, Windows-based PC.
1. Download the individual files in this Google Drive folder to a Windows computer.
2. Behind the door of the Trofa machine, locate the four nuts affixing the retaining bracket of the Nexus tablet. Unscrew these and remove the tablet, carefully unplugging its USB cable.
3. Connect the tablet via a micro USB cable to the computer. Once connected, simultaneously hold down the power and volume down buttons on the side of the tablet, continuing to hold through its reboot until it arrives at a black screen with a green Android logo.
4. Run the adb-setup-1.2 installer, typing Y and Enter at the two prompts (see video below). After installation, open up a Windows command window (Start > Run > cmd). Type fastboot devices and hit enter. If the tablet is recognized, you'll see a string of numbers/letters followed by 'fastboot'.
5. Run the following commands individually, replacing C:\path\to\sencha.bootimg and C:\path\to\sencha-system-generic.img with the location of the image files on your computer. You can get this by dragging and dropping the image files onto the command window after typing the preceding parts of the command.
The 'unlock' command will require selecting 'yes' on the tablet via the volume up/down buttons, and confirming by pressing the power buttons. Afterwards, you may continue with the rest of the commands.
fastboot oem unlock fastboot oem off-mode-charge 0 fastboot erase boot fastboot erase userdata fastboot format userdata fastboot erase system fastboot format system fastboot flash boot C:\path\to\sencha.bootimg fastboot flash system C:\path\to\sencha-system-generic.img
6. It will take a couple of minutes to flash, finishing with 'Success'. If you receive a 'Failed' message, try a different brand USB cable and port on your computer.
7. After a successful flash, restart the tablet while it's connected to the PC or a wall charger. Connect it to Wi-Fi, then let us know to update it.
8. After we've pushed the first update, press the 'INIT' button that appears on screen. It may take up to 10 minutes to complete. When the tablet goes to the 'Maintenance' screen, reboot it by holding down on the power button. Then, reconnect it to Wi-Fi and let us know to push the remaining updates. After these, you'll be able to pair it to your server and connect in your machine.