car lcd light does not light up need help

I have a car CD-player
it has a detachable front panel with RDS and plays MP3s etc.

The problem is that the LCD screen does not light up so thus I am unable to see any of preset radio stations or the cd track that is playing.
It worked before but does not work any more.
How can I get the LCD light to display?
replace the flat flex cable inside the unit. it connects to the face plate and main circuit board. It can be difficult to replace.. It breaks after flexing so many times with the movement of the face plate