EL Panels have been used as display backlights in consumer and professional electronic equipment for more than 30 years.

They have proven to be very reliable but if the unit is still being used after more than 10,000 hours of lit display then these will start to fade so much that it becomes unreadable.

Instead of replacing the entire screen, an inexpensive EL Panel backlight replacement can be inserted instead. There will be some disassembly and soldering involved but there are usually youtube videos for the procedure for most makes and models.

These EL Backlights will have to be soldered into place and if it is not quite the right size you can trim it down to shape with scissors, never a scalpel blade and ensure that you re-seal any 'cut' edges with glue.