Initially called out to perform an inspection of the system to determine the location of a refrigerant leak. Visual inspection did not show anything, advised customer we would have to perform a nitrogen leak search and the leak search was accepted. Leak search showed the leak was coming from the filter drier located outside. Filter drier was resting on the ground and this caused corrosion and eventually a leak. Searched for leaks that could be inside of the wall and to the best of my ability did not find anything. Sent estimates for repairs and photos/videos of the leak location.