eddy_c

Hi, don't know if it might help, because I have a TX3 Mini with a 1.2 board,  but if yours can dualboot stock Android (Alice UX) and LibreELEC, like mine does, then perhaps they are similar enough.
On mine, pressing the reset button does nothing either, in order to boot from SD card I have to:
-boot on the stock Android first;
-open the upgrade & backup app;
-press on select an upgrade package;
At this point a menu will pop-up and after a brief search the app should find, on the SD card, an "aml_autoscript.zip" file, which I guess is a package the image creator has made in order to trick the upgrade app into thinking that the Armbian image is an upgrade package, but anyway, select it;
-press the upgrade button;
The app ask if you're sure, would you like to make a backup first, yada yada, click ok and it should reboot for the firmware upgrade;
On reboot, instead of the firmware upgrade that Android expected, you should have Armian booting, no need to press buttons or anything, just click reboot and wait to be prompted to input a username and password.
 
Since I have no wi-fi (my TX3 has the dreaded SV6051P SDiO Wi-Fi and BT chip) and since many around the forums claim that they fixed it by changing their dtb, I have tested several dtbs:
meson-gxl-s905w-tx3-mini.dtb
meson-gxl-s905x-p212.dtb
meson-gxl-s905w-p281.dtb
meson-gxl-s905x-nexbox-a95x.dtb
All of them worked, meaning that I could boot into Armbian no matter which one of them I used, but I noticed that audio through HDMI works on the s905w ones and not on the s905x ones (sometimes I had no HDMI audio on s905w either, just try reflashing the SD card if that happens).
None of them fixed the Wi-Fi, none of them had hw acceleration for videos (meaning that video playback relies on CPU and it sucks), no IR remote, no VFD, no audio from the AV jack, but that was to be expected.
 
Since we're on the subject, I wanted to ask SteeMan (the man who owns 4 TX3s, with different board revisions) if he managed to get the Wi-Fi to work on any of them and if yes, on which ones.

But anyway, yeah, let me know if that works.