When you manually assist the opening, does it complete it's excursion on it's own and then close on it's own? Or do you have to pull it all the way open, and push it closed?
Also does it play the disc without any errors?
One thing you may try if you haven't is unplug the unit and press all the buttons on the face plate while it is unplugged. Then leave it unplugged for 30-40 minutes. This will eliminate any stored capacitance in it's memory and force it to return to it's factory defaults. If upon restarting the unit it continues to malfunction, then find a reputable repair center and have it further diagnosed. It could be a simple switch or a transport.
Also does it play the disc without any errors?
One thing you may try if you haven't is unplug the unit and press all the buttons on the face plate while it is unplugged. Then leave it unplugged for 30-40 minutes. This will eliminate any stored capacitance in it's memory and force it to return to it's factory defaults. If upon restarting the unit it continues to malfunction, then find a reputable repair center and have it further diagnosed. It could be a simple switch or a transport.