Do you have the original Pi3 psu?
[edit] It is, in all likelihood, a PSU issue - the official FAQ states ''The board is powered by +5v microUSB port. Exactly how much power is required, in terms of current. (mA), is depending on what you hook up to the board. An official 2.0A (2000mA) power supply is available at the Pine64 store with ample power to run the board for most applications.''
[edit] It is, in all likelihood, a PSU issue - the official FAQ states ''The board is powered by +5v microUSB port. Exactly how much power is required, in terms of current. (mA), is depending on what you hook up to the board. An official 2.0A (2000mA) power supply is available at the Pine64 store with ample power to run the board for most applications.''