The problem is the following. We were using the oscilloscope in normal regime, reading the data via remote control from PC. Suddenly we've noticed that the display is dark. Before that, it was operating normally, including touch screen control. Except the display, everything works well, the signals are digitized properly. We rebooted the oscilloscope several times, but the display couldn't be turned on anymore.
Could you please advice what to do?
By 'remote control from PC', I assume that you mean using SCPI, VISA, or something like that?
Is there a chance that you have sent a ":DISPlay:BACKlight OFF" command? If you have Keysight IO Libraries loaded, you can use interactive IO to send ":DISP:BACK ON" to see if it turns on.
Al