You will need the power switch once you operate mobile from a battery. If you dont want to solder the switch to the board, the switch pins are also on the small EXP header where you can for example just attach:
http://www.ebay.com/itm/ATX-PC-Computer-...SwEjFXcQaS
The button connects to GND so you can just plug that in between Pin 5 (Pwr/Stb) and Pin 6 (GND) on the EXP header (page 3):
http://files.pine64.org/doc/Pine%20A64%2...160119.pdf
http://www.ebay.com/itm/ATX-PC-Computer-...SwEjFXcQaS
The button connects to GND so you can just plug that in between Pin 5 (Pwr/Stb) and Pin 6 (GND) on the EXP header (page 3):
http://files.pine64.org/doc/Pine%20A64%2...160119.pdf
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