Hello! I recently started to play with this box and couldnt boot anything at all, as if reset button on AV port didnt work. So I downloaded terminal app for android and typed "reboot update" as suggested here https://forum.libreelec.tv/thread/4076-mxq-box-won-t-boot-into-sd-card-le-or-recovery/?postID=29844#post29844 (toothpick method doesnt work at all), and managed to enter recovery, so then I put ARMBIAN on SD and did "reboot update" from Android and booted Armbian. It worked fine...
Until I wanted to try LibreELEC or EmuELEC and now the box doesnt boot Android (stuck at MXQ 4K Pro logo) and wont boot anything on SD as LibreELEC, EmuELEC, it only boots Armbian images. I can't even flash any IMG with Amlogic Burn Tool as device never enters flash/recovery mode with toothpick, so I think the only chance is to do something inside Armbian. I suspect recovery on this box is somewhat flawed, it seems to be "stuck" on "update mode", so all I can think is a TWRP compatible recovery flash from within Armbian, or any other recovery that works, so I can go back to Android or try EmuELEC.
Device is OTT MXQ Pro 4K, AML S905 1GB ROM 8GB RAM, Realtek Wifi, GXBB P201, it uses "hugsun_s905_mxq_20160304.img" Android. Armbian works fine, nothing else boots.