I have a Jensen JCD2010 CD player/receiver in my Zinger. There is power to the unit, but there is no display. Nothing happens when I push the reset, the buttons and dials. The display is blank. It is probably due to me hooking the wrong cables to the RV battery posts. I suspect it is a blown in- line fuse in the player. I managed to get access to the in- line fuse, but there a black plastic covering. How do I remove it?