Radio security message

Hi All.Got a second hand radio with code for my Disco 1 300TDI 1995. Unfortunately I put the code in wrong.Now I get the message security on the set.I have turned the key ignition to position one and waited a number of hours for the radio to reset,but it hasn't.I have disconnected the battery overnight (19 hrs) reconnected,put the radio Key at position one and switch on the set but it still reads security.Can anyone help.
Many thanks.
306james

Tell us what head unit u have would be good.
Put a picture up of the head unit as the word SECURITY is not for a standard Philips head unit, WAIT, CODE, CODE IN are the usual ones.

sounds like you tried the incorect code to many times , on most coded units i have dealt with if enterd to many times its scrap , try taking it to a instalers like to boy racers use they may be able to permanalty decode it