If your Douro's tablet no longer boots due to data corruption on its internal drive (see 'Powering on and off the Douro'), then the drive may be recovered by flashing it to factory settings.
To do so, you will need a USB flash drive (8GB or higher and preferably USB 3.0), a USB keyboard, and a computer to create the recovery USB drive with (Linux, Mac, or Windows).
The process below is for Douros shipped after January 2017 featuring an ACP-1104 model tablet.
If your machine's tablet features a blue USB 3.0 port next to its power button, then use this guide.
If all USB ports are black, then use the instructions for the flashing ACP-1103.
Creating the recovery USB drive
Download the image for the Lamassu Flash Utility (3.1 GB): https://lamassu-images.ams3.digitaloceanspaces.com/lamassu-flash-utility-1104-351.img.xz
Download and install Etcher (available for Linux, Mac, and Windows): https://etcher.io/
Open Etcher, select the Lamassu image file, then select the destination USB drive and click flash.
WARNING: Be very careful when selecting the destination drive, ensuring that you correctly point it to the destination USB drive and not that of any other devices you have connected, as the command will result in full data loss to the destination.
Booting to the USB drive
Power off the Douro with a single press and release of the power button at the top of the tablet.
Insert the now flashed USB drive into the blue USB 3.0 port on the top of the Douro's tablet.
Connect a USB keyboard one of the tablet's other USB ports.
Press the tablet's power button, then repeatedly hit the DEL key on the keyboard until the tablet boots into the BIOS settings screen.
Select the USB drive as the machine's boot drive, then save and exit. (screenshots here)
Flashing the tablet
When the tablet boots into Debian and you are prompted for a username, type root and hit Enter.
For the password, type password and hit Enter. Note: nothing will show on the screen as you're typing, as password entry is hidden on Linux.
To reflash the tablet's internal drive, simply type flash and hit enter.
The flashing process may take up to 30 minutes. See the screenshot below for the expected output:
When it's complete, type shutdown now and hit Enter.
Booting to the internal drive
Remove the USB drive but keep the keyboard attached. Press once on the tablet's power button, then repeated hit DEL on the keyboard to boot into the BIOS.
Reverse the changes you made earlier to the boot selection, re-enabling the mSATA drive as the first boot option.
In the BIOS, choose 'Save and exit', remove the keyboard, and close the machine door.
Pairing and updating
When fully booted, press the INIT button on the 'Congratulations' screen. Once initialised, create a new pairing code from your admin as you had done originally to pair the machine, press the Pair button and scan the pairing code.
The version contained on this machine image will be older than our latest release. Once paired to your admin, please use this article to retrieve the machine's device ID and contact support so that we may update your machine.