Radio display

Recently the radio in my old 96 Corsa B died.it had the 201S,the only replacement I could find was that was supposed to be compatible was the Philips Car400,,got the radio and code,fitted the radio and put the code in and the radio and tape works fine,however the top display that should show what station it is tuned to does not,.I've been told that there is a sequence to switch the display on and off but not having the user manual I don't know how to do it,if anyone knows I would be very grateful for your help.
Thanks in advance
Jim