I’m guessing that the power supply for the screen has quit.
I have read of some systems where the surface internals accumulated an over abundance of dust/dirt thru the ventilation, thus causing the power supply to overheat. I don’t recall if it just blew a fuse that could be replaced or if the entire power supply unit had to be replaced.
In the meantime, if you have a windows laptop and can connect to the ACE network, there is a program that you can run that will give you your screen display/functionality on the laptop(except that it is not touchscreen, you will need to use the mouse).
The program is called, “DL5000SystemManager.exe”
The file is normally located in the firmware update package of files. You can download the firmware update package that includes this file if you don’t already have it.