Sony VHS recorder/DVD recorder programing problem.

I have a Sony VHS/DVD recorder, Model RDR-VX525. I changed the command mode for the recorder from the factory default of DVD 3 to DVD 1 which made it unable to operate (cannot change or get a menu to change). Does anyone know how to get it reset to factory defaults? I took it in to a repair shop and they couldn't figure it out and Sony web site is no help. Hope someone can help me.