pioneer deh p860mp

I have a DEH-P860MP with a non-working motorized faceplate. When you push the 'open' button the unit beeps, but the faceplate does not open. Any ideas what may cause this? This was originally an intermittent problem. Now it seems permanent. The unit makes no mechanical noise when the button is pushed, just the confirmation beep. This leads me to believe the problem is electronic rather than mechanical. I've heard that the ribbon cable between the main unit and the faceplate mount frequently goes bad in these models. Does that seem like a reasonable cause? Pioneer does not list the ribbon cable as a replacement part on their web site. Any idea where I might get one? Any info would be great. Thanks.Paul Romaldini