Head unit CODE ... yes this thing again

[Burn535i]

So I recently took my car out of storage, and because the battery was disconnected my head unit now wants me to input the security code. I got the code off the card in the back of my owners manual, followed the instructions, and yet it would not accept the code, and yes it is the right one. Any suggestions.

[dansgt]

get a good aftermarket one?

[NikosX]

If you punched in the code incorrectly three times, it will not let you back in.

The radio has to be left ON for an hour to clear the codes.

[Testercles]

My bad for reviving an old thread but I'm having a similar problem... I can't find how to enter to code. No matter what I press on the head unit all I head is a loud beep and nothing else happens.
Is there something I have to press down whilst entering the code or...? And how many digits is the code?

[ShapeShifter]

It beeps when the wrong number is pushed.

[Testercles]

It beeps no matter what I push.