Does anyone know how to press 3 front-panel controls at the same time to default an older Panasonic DVD Player/Recorder back to the factory settings? I refer to models such as the DMR-E20, DMR-E30, DMR-E50 ,etc. I find some information by Googling, but not exactly what I need. Panasonic has started charging for customer service information for older units. On some of the players (not also recorders) one generally pushes OPEN/CLOSE - REVERSE SKIP - PAUSE (or STOP) at the same time and holds them for several seconds until the display shows a factory reset. I tried similar things on the player/recorder with no luck.

I have the manuals and this information is not in the manuals.

Thank you!