Hi again Ken... I've just looked up the radio you have named in your last post in my Vauxhall Audio Manual - it's actually the second one listed in the book - an RDS, FM radio with an in-built cassette player?
The security system is virtually the same as for the CDR 500 I quoted the unlocking sequence for earlier. When it shows SAFE, it means it is properly locked. If you press the AS control and hold it depressed while turning the radio ON you should hear an acknowledgement tone after about 3 seconds. Only then release the AS button. The SAFE display should then turn to "10....." -if you have 10 tries left to input the code. If you have already put in the wrong code, it will show less tries left, ie. "8....." -if you have already tried twice. After 10 attempts to input the 4 digit code and getting it wrong 10 times, the display reverts to "SAFE" only with no numbers or dots, and then the set can only be unlocked for more code input attempts by a Vauxhall Dealer.
So if your display is only showing "SAFE" without any numbers and dots, it looks as though you have unfortunately reached the end of the line, and will need to take it off to the local Vauxhall Dealer to get it unlocked....! Cheers.. Robin