I have a Marantz sr5011 without a remote. I found what's seems to be a working device code (492) that does everything except for the OK button. That's the one in the middle of the directional buttons. I have a harmony where the OK button works fine and I have tried to get the MX-700 to learn the code but nothing works. If I do it for the OK button it says succeded and a little l is on the button but it's not working. I have tried a spare button, e.g Pre Channel button, and a device button but nothing takes. Any Ideas?