If the front panel display of your OPPO player turns off or seems unusually dim after powering on the player, it may be due to inadvertently pressing the Dimmer button on the remote control. This button adjusts the setting for Front Panel Brightness as found in Setup Menu / Device Setup.
Each press of the Dimmer button will allow you to cycle through each of the three brightness options: Standard(default), Dim, and Off. When a setting other than Standard is selected, the player will either dim or completely turn off the front panel display. Pressing a button on the remote control will result in the front panel display activating at full brightness temporarily when the Front Panel Brightness setting is set to Off.