If you now  have the correct code then start the procedure to enter the code....(ON button plus another?...**see below) ...then leave the radio switched ON ....UNDISTURBED ...for as long as it takes to reset itself automatically.(with 7 ERROR it should be around a couple of hours)
Then enter your code as normal.
**Entry info here
http://www.davidsonelectronics.co.uk/code_entry.htm
                
 RegWorts
                
 June 2008