We're on our 2nd MX-500, but it's seen better days. The backlight is gone, something is rattling around inside. Time to get the replacement before the world comes to an end. I'd love to just buy a new MX-500 and do the programming dump--love that feature--but I can only find used ones. Is it possible to dump the programming of the MX-500 into other MX models, like the MX-850?