My Audi Concert II cd player works fine with playing cd's and the radio etc, no problem

The problem is, is that in the dark when the headlights are on the lights on the unit DONT light up!!

The display is all fine, it's just the little LED lights dont and I cant see what the buttons are in the dark bcos of this!

I have bought a different Concert radio from Ebay and tried that and STILL the same issue!

Any ideas as to why this has happend??!! Or do you know of any Car Audio Specialists in the Teesside and North East area