Issues

From OpenEZX

A780

The phone does not charge with the USB data cable

Perhaps your phone is completely discharged. At this point you need to use the USB power supply. Take a look at A780#Charging_modes.

The phone does not charge on my USB hub

The device you connect your phone to must supply about 500 mA (milliamps). When plugged into a keyboard with a built-in USB (for example), the phone will not charge (Windows will notify you of this). This is because the keyboard does not provide power. Other devices may provide power, e.g. so-called self-powered hubs.