My radio has worn out in my micra passion. A family friend has donated the identical radio out of her car (was taken out shortly after purchase as she had a CD player fitted). We've fitted the replacement to my car but when we switch it on it just says "WAIT" then "SECURE" and doesn't give us the chance to put the code in. We've tried disconnecting the battery and reconnecting it - no change

Anybody got any ideas on how to fix this?