It was the last update which was provided by Google for this device:
- Android Update 5.0 (11.2014)
- Android Update 4.4.3 (6.2014)
- Android Update 4.4.2 (12.2013)
- Android Update 4.4 (11.2013)
- Android Update 4.3 (8.2013)
- Android Update 4.2.2 (2.2013)
- Android Update 4.2.1 (12.2012)
- Android Update 4.2 (11.2012)
- Android Update 4.1.2 (10.2012)
Without a battery it is not possible to startup the device - only power over USB is not enough.
So i disassembled it like described here and added some cables to connect a battery from outside:
So i booted TWRP onto this device:
After that i was able to install lineageOS via adb sideload.root@zerberus:~/bin# fastboot oem unlock (bootloader) erasing userdata... (bootloader) erasing userdata done (bootloader) erasing cache... (bootloader) erasing cache done (bootloader) unlocking... (bootloader) Bootloader is unlocked now. OKAY [193.432s] Finished. Total time: 193.433s root@zerberus:~/bin#fastboot boot ~/Downloads/twrp-3.0.2-0-grouper.img
Now the device has nearly 6GB space left:adb sideload ~/Downloads/lineage-14.1-20171122_224807-UNOFFICIAL-aaopt-grouper.zip adb sideload ~/Downloads/open_gapps-arm-7.1-pico-20200415.zip
I can use the play store and the device runs on Android version 7 - and it runs youtube movies without any interruptions...