Very Dim Display Screen

[DRTFX35]

On my 2004 FX35 the display screen dimmed down to where the backup camera is hard to make out clear images. I notice that when I turn on the lights it gets better (still not good) but I do not want the lights on all the time. The backup camera is really helpful because looking out the rear through the windows in the FX can be challenging. I am thinking that maybe I just replace the screen, but that may not be the problem - perhaps its the signal going to the screen that's weak.

Any thoughts? Thanks in advance.