WR250r LCD no Backlight

hello, I am trying to figure out why the LCD screen does not have a working back light? does anyone know how to fix this?
thank you in advance

I'm pretty sure the backlight is solid state (not a replaceable bulb) and is on whenever the bike is on.  I reviewed the wiring diagram prior to replying and don't see a dedicated wire for the backlight circuit.  There's also no mention of this in the list of replaceable bulbs in the owner's manual.

I've read about this twice before, here and here.  Neither appear to have found a way to fix it.

thank you for all your help. so what options do I have? also do you know where I can download a service Manual for my bike.
thank you