Nissan Primera P12 Radio saying "Secure"

After having a new battery fitted the radio didn't work and the "secure" green screen appeared. Tried disconnecting the battery for 30mins as suggested here but it didn't work and to make matters worse it has caused the CD player to give out a constant bleep and lights on it to flash. Can anyone help please?

Thanks for that, gave it another try today as you suggested but it hasn't worked. The local car radio experts say the unit needs taking out and sending to Nissan for repair at vast expense. I can't see how changing the battery can damage the radio and a problem in re-linking to the ECU seems more likely. Any other suggestions or experiences would be welcome. With the CD how can I tell if there is a disc in it? The thin slit for the CD has a piece of plastic in front of it that wont move and doesn't let you see in and the arrowed button on the right does nothing. Is it a multi CD unit? What do the row of buttons along the front normally do? Thanks for any help.

If its a 6 cd player it will have 6 buttons along the front face.
If no cd is in the unit these should all be lit green which changes to amber with a cd in that particular slot.
The silver button is the eject, so to eject a cd press the associated disc button then the eject and assuming a disc in it should come out.
An anti insertion bar will drop down when the unit is fully loaded to prevent any more discs going in.

What was running thru my mind here is, if a cd had been left in the unit and it became confused with the battery change it may have caused the lock out.

robertgroves wrote: Hi again, Re: green secure warning, i have been told that it is not a radio fault, but a fault within the anti theft system. Disconnecting the battery for 30 mins cures it, but it happens again at random intervals. i have fitted a battery switch to the earth side to avoid having to disconnect the earth lead every week or so

Thanks for the feedback.
Sorry you have had to Frig your car to get things workings but it has triggered a thought in my mind with regards the earthing in the P12.

The P12 has multiple earth points and I now think it would be worth investigating as many earth points as possible.

Crack them open then redo as many as you can find.

If your multichanger is in the dash I am assuming your P12 is 04 or later (big silver handles inside the car), if so, if sat nav was fitted the DVD player is located under the front passenger seat visible from the back seats with the front seat full forward