Sent this email yesterday. 15 July
I’ve shot myself in the foot, again. In present day chess tourneys it is required to switch off your phone during games. (To prevent cheating.) I fear I switched my off during an update. (Because of cheating it is now a requirement to switch phones off in chess matches.) It now loops in the boot as far as the Google G and then powers off again. When it blacks out after the G by holding down VolumeDown I reach the fastboot lock. (This post similar to https://support.nitrokey.com/t/how-to-perform-a-factory-reset-and-request-repairs/7610 )
I have attempted to unlock from both the GrapheneOS WebUSB installer and the cli method (I wiped Qubes from my NitroPC and installed Arch to bare metal as recommended by the GrapheneOS team to reinstall.)
$ sudo pacman -Syu android-udev android-tools
### /usr/bin/fastboot is already installed.
### plugged in the phone on a usb-C to usb-A 100W/ 20Gbps cable on a rear port (usbC to usbC failed to work)
### kded6 sees the attachment
$ lsusb
…
Bus 002 Device 013: ID 18d1:4ee0 Google Inc. Nexus/Pixel Device (fastboot)
$ fastboot flashing unlock ### with or without sudo
FAILED (remote: ‘flashing unlock is not allowed’)
fastboot: error: Command failed
I presume this is because Developer Tools have not been allowed on the phone itself. Lastly in addition to the recovery mode mentioned in Alexandre’s reply mentioned in 7610 above https://discuss.grapheneos.org/d/9538-how-to-factory-reset-from-recovery-mode there is also a rescue mode. Switching to either of these on the phone simply down-powers back into the boot cycle as far as G and power off again.
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16 July update. Did a lot of digging around. Read a lot on grapheneos forum. Tried lots of button sequences. Power+Volume Up gets nowhere. Nor does anything else.
flash dot android dot com proved to be of no help. “Cannot unlock the phone” or words like that. It seems it needs far lower-level tools to fix this. Probably the whole firmware needs to be wiped and reinstalled. The recovery partition probably corrupt and therefore cannot be accessed. Google reckon the phone is still under warranty until April 2028 (from the IMEI number). However, does this mean I should ship it back to Nitrokey from the UK or would it be simpler for me to take it to the nearest Google Authorised repairer (an EE shop ~60 km away in Cardiff). Would not be surprised if they won’t take it.
Many thanks for any suggestions.