Bosch gas Analyzer

Question

My 15 year old bosch Gas analyzer has lost its memory because a small button battery that I did not know it even had has gone flat. I have fitted a new battery but can not reset the program. the manufacture Bosch say that it needs a new board as it can not be reset by the user.but the board is not available and it seems an awfull shame to scrap such a good machine just because it needs the programe reloading. Can anybody help.