Raymarine E120

I bought a boat with an E120 Classic and I cannot get the backlight strong enough, in DAYTIME MODE to see the screen well.

Can someone help me please? I am in Curacao, Netherland Antilles so it is not easy to get stuff repaired here. This unit has been used very lightly and if I cannot get it repaired, I will need to go through a whole lot of expenses to update a fairly recent system.

I always had Raymarine products on my boats...

Please let me know what is next.