Pine64 won't boot

[MarkHaysHarris777]

I decided to re-flash Android 6.0.1 on my Mac (using either dd on terminal, or Etcher) with three 16GB and 64GB cards. But nothing happens. The led lights up for a pair of seconds and then switch of, with no boot, nor display on the LCD. Any idea of what is going on?

This symptom is almost always a power problem.

...  make sure your board is powered via 5v @2.5A switching PSU ( not charger ) via the euler bus pin(6  +5v) and pin(4  -ground).  Avoid using the micro usb connector for power;  it does not handle the current well, and often is not soldered properly ( cold joints ).

Usually when the pine board appears to not boot , it really is booting , but the video output is having problems for some reason usually because the monitor and the hdmi mode line of the pine are not behaving well together.  You can prove this ( and or get around it ) by using a serial console to monitor the bootup process.  Use a serial bridge cable TTL usb from your PC to the pine board EXP header Tx-->pin(8),  Rx-->pin(7),  ground-->pin(9).

( If you're using the LCD, make certain your image is an LCD image; that the configuration is set for LCD. Re-seat all connections and make they are tight and square. )

You can then use either 'screen' or minicom on your PC or mac to watch the bootup ( should it boot up you can also logon to the pine board via the serial console ).