Search For All Instances Of A String

I'm using the following code which is working well. It finds an instance of the string "A83". Once it finds it, it moves down x number of cells and populates it with a new string. It then moves down another x number of cells and populates it with another new string, etc.

The problem is, it is only looking for "A83" one time and performing the appropriate actions at that point. What I need to do is look for *every* instance of the string "A83" and perform the appropriate actions.