I've been playing around with LibreELEC S912 development on the U9 and went to "reboot to internal", which is normally reliable and all I could get was a black picture video output from the U9 when trying to boot into Android from that point onwards. I've seen this before when Android devices with HDCP - copy protection - where the Keys get corrupted and then you can get no video & sound output out of the device at all. Anyway this is the quick fix recovery method (should work on all AML Android devices): 1) Save this code to a plain text file called factory_update_param.aml (there must be no .txt extension) Code: --wipe_data --wipe_cache --update_package=/udisk/update.zip 2) Download whatever U9 Firmware file MINIX are currently using - eg U9H_FW004A.zip Rename this to update.zip 3) Unzip the file in Step (2) and extract the recovery.img 4) Save these 3 files to a USB Stick: factory_update_param.aml update.zip recovery.img 5) Unplug the power from the U9, insert the USB Stick. Plug in power again and then press and hold in the power button for at least 6 seconds. The TV screen will still be black, but... I could see a flashing LED on my USB stick, indicating activity. And after approx. 7 minutes the MINIX desktop appeared again with all my Apps still intact. W.