Hi
As far as I am aware, I could be wrong!, there is no 24LC641, so its probably a 24LC64.
Eeproms rarely actually fail nowadays, usually just corrupt data. I would save the current contents then erase it and try it like that, hopefully the micro will load default data to get the set going. Or you could just fit a new 24LC64 if you don't have a programmer.
Good luck
Keith
