I am using a URC MSC-400 to control a Yamaha RX-V1900. I'm using the RS232 command strings in the URC database. Most of the RS232 strings work correctly - power on/off, input selection, etc. are working properly.

However the command for displaying the onscreen setup menu does not appear to work. In the URC database this command is named "GUI Operation Menu". And yes I do know that the URC RS232 database erroneously uses extra "\" characters to represent hex numbers in ASCII strings, and I have removed the extra "\" character in all the command strings. So the command string I am sending for the GUI operation menu command (in ASCII) is: \x0207AA0\x03.

Sending this command string does absolutely nothing. Interestingly, the RS232 codes for moving the GUI cursor up and down do seem to work. If I press the menu key on the Yamaha remote to enable the menu via IR, I can then use the RS232 commands in the URC database to navigate through the menus.

I also checked the RTI RS232 database and it has the same RS232 string for the menu command.

Does anybody have a working command string for the OSD menu command? I have the Yamaha protocol docs but they are a bear to deal with and I don't really have the time to try and decipher them.