If your OPPO HA-1 appears as though it is immediately powering off after powering the unit on, it is likely due to having set the Screen Dimmer setting to Off. 

A quick way to determine whether the unit has actually powered off is to turn the volume knob on the HA-1. If the Screen Dimmer mode is set to Off, the HA-1's display will briefly turn back on to indicate the current volume level when the volume knob is turned.

The Screen Dimmer setting can be adjusted via the HA-1's user interface, or by pressing the Dimmer button on the included remote control.