I was called to a home to address a unit freezing issue. Upon arrival, I found that all the supply vents in the finished basement were closed, and the return drop was covered with a cheater vent. I opened the vents, and the subcooling was good, but the temperature split was not optimal. I adjusted the supply and return air dampers to improve the airflow and temperature distribution. I also checked the condensate drain and found that it was clogged, so I cleared it out and tested the system to ensure it was working properly.