One day I was driving and my clock on the dash back light just went out.so the 1st thing that came 2 mind was to give it À little tap,after I did that it just cut back on... so I never thought nothing of it. But then the light just cut off completly I try tapping and it didn't work so I went and bought À new clock and the new 1 works but the back light doesn't come on...and 1 know what could be the problem