QUESTION 

Can a damaged load cell be repaired or does it need to be replaced?

ANSWER

If the load cell was crushed and its zero-load offset reading is beyond 2% it must be replaced.   This means the load cell has plastically deformed.  A 2% or less offset can sometimes be taken out by the software.  

If a wire was broken it can usually be repaired.  If the load cell underwent known crushing forces beyond its full-scale capacity and is reading an offset it is likely plastically deformed and not the result of a broken wire.