Our car has an aftermarket CD radio headunit, Sony CDX-S2010, and it has a removable face plate. The buttons on the face plate no longer function, nothing works. Sometimes the volume will go up by itself, and sometimes the face plate won't light up at all. So I'm not sure if the problem is in the headunit or it just the face plate malfunctioning. Any ideas or suggestions. Thanks and God Bless you.