Unplug HDMI when connecting Power or sometimes it doesn't boot

Do NOT use this image: Debian-8-jessie-mate-gpu-bpi-m3-sd-emmc.img 2016-5-16 - after Upgrade it's broken, because it contains an incompatible armbian repo. Check:

dpkg -l | egrep "armbian| linux"
cat /etc/apt/sources.list.d/armbian.list  # remove armbian line, if exists

Use a more recent image: http://forum.banana-pi.org/t/bpi-m3-new-image-raspbian-jessie-bpi-m3-img-2016-07-13/2009

Just edit /boot/bananapi/bpi-m3/linux uEnv.txt file

or use sunxi-tools to convert the bootscript to fex and change this:

hdmi_cts_compatibility = 1

Full manual: http://forum.banana-pi.org/t/how-to-the-final-solution-of-compulsive-modification-of-hdmi-output-resolution/1442

Edit /boot/bananapi/bpi-m3/linux uEnv.txt: There are some Example “bootargs” lines. Use one of those or append something like:

 disp.screen0_output_type=3 disp.screen0_output_mode=10 disp.screen1_output_type=3 disp.screen1_output_mode=10

type:3 mode:10 = HDMI 1080P

Find more Mode Numbers here: https://bananapi.gitbooks.io/bpi-r1/content/en/compulsivemodificationofhdmioutputresolution.html