I tried to downgrade ADT-3 from Android 12 preview to Android 11 image from https://android-developers.googleblog.com/2020/06/android-11-dp-on-android-tv.htm , but the device is bricked and stuck at "androidtv" logo page.
How do I put ADT-3 in recovery mode to flash ADT-3 facteory image?
Help despearately needed.
What is your experience level? It appears to be just a ordinary Amlogic SoC device with a reset button.
I don't have that particular device, but I think you can get into the recovery menu by depressing and holding the reset button as you power own the box. I use a small paper clip to reach the reset button under the hole in the case.
Of course you have to have downloaded the zip file an copied it to a microSD card formatted in fat32.