Did you recently get this repaired at a repair shop? If it is, its probably a low quality LCD. If it’s the original screen that the backlights are intermittently going out.
Maybe the drum is out. Its common with laser printers. If you google the make and model of your printer on google, you should be able to find what type of drum the printer uses.
You could possibly try to find a replacement pad and connect it and see if the new pad works, if that’s the case, then its possibly just an old pad that just went past its due date.