How to Troubleshoot & Replace Samsung AP5326112 / DA97-07190G Evaporator Cover

I purchased the service manual from Samsung (thumb drive or CD, took a few days in the mail). It was handy for doing some self tests and operations, very similar to codes and tests on cars. Ultimately every part tested okay. I broke the evap. cover because it was still frozen when I pried it off. After a complete thaw it seemed that somehow the evap. drain was restricted so water built up and refroze until it was touching the evap. fan blades, which we could hear and tipped us off to a problem. Before reassembly I wrapped a 14 gauge copper wire around the defrost heater element a few times and then snaked it down the evap. drain several inches to prevent drainage from freezing and plugging the drain. Its been a couple weeks and so far so good. 

Replaced this part and evaporator thermostat and evaporator heater along with this part.