Condensor fins fell off while cleaning

LadyTech , If you were just using the same cleaner as you normally would, non/minor corrosive, you answered your own question, Bottom rows very dirty, probably hidden corrosion behind the dirt and entirely possibly the dirt was about the only thing holding fins in place. It is pretty much the same for automobiles aluminum condenser's and radiators, bottom rows deteriorate very quickly. I have seen people at the car washes think it is a good idea to wash the bugs/debri from their car's A/C condenser and all of a sudden there is all sorts of aluminum cooling fin/strips blasted out laying under their car and always the lower coarse's, while the top are strong and like new. You may want to try a finger/minor destruct test on the next unit prior to cleaning, push on the upper fins and see the force it takes to bend the fins then go to the lower coarse and see how easy it is to bend/fold them over or if brittle just rip/tear. If they bend very easily, you will have to take extra caution and tell the customer of the condensers condition. Also who knows what chemical had previously been applied or sprayed on the unit the last time it was serviced. Hope this helps.