Red LED during first boot

Hello!

Ubuntu was burned and works Ok. I was trying to get CoreElec on SD card over Ubuntu, but Green Interface was a problem and I decided to move to Android EMMC image.

Tried both Android 190809 and 190907 on Windows using TST mode and Burning Tool 2.1.7.3 - burning successful, but during first boot, after Khadas Logo and 1 minute of waiting I received black screen and Red LED together with White LED. Sometimes screen is flashed for fraction of second.

Can’t find info about meaning of red LED in docs. Could you advise what to do next?

Thank you

Update: Problem was with HDMI cable or projector - I didn’t see a process and loaded OS. On Monitor with other HDMI all is Ok - Android and CoreElec is running.

@bongiozzo Do you use external power supply?

5V 3A
It was from RaspberryPi 3

Just double confirm here: you already figured the problem out, right?

Have fun!