Rotel RSX 1055 RR 1050 : OSD not working

I have a Rotel RSX-1055 with RR-1050 remote.
I have connected the MONITOR OUT Composite on the RSX 1055 to an input on my TV (Philips Magnavox, 1997).
I am not able to view the On-Screen display on pressing the Menu button or by pressing the "Enter" button when the unit powers up.
Has anybody run into this problem or has any suggestions to resolve this?
Thanks.