Try

Menu>Set-up>Help>1397>Reset PIN>OK

This should return it to the default '0000'

You should be able to deactivate the child lock from Menu>Set-up>Child Lock>0000
then set maximum certificate to 18 and Enable Lock Period to 'No'

hope this helps

regards

You are having a parental lock on your tv .
You need to provide password to unlock it .