surrounds stopped working. Why?

Have kenwood krv7070 new since 1995. Just pulled out from 5 yrs in storage. Hooked all speakers up, ran sound test and all speakers tested good. Placed speakers and ran wiring. Surround no longer work. Checked everything, still no sound. Replaced wires with new monster wires,still no sound. Went through manual, nothing worked. Any ideas why surrounds worked, now don't?