I can't remember the brand name of the Plenum/coil combo but some of you probably have seen them. Checking a unit, it was frozen. Shut off condenser and returned the next day.
Re-started system and was checking the super-heat when it plunged. Shut system down and checked evap coil. Some brainiak removed the horseshoe style original coil and very carefully installed an A frame coil. They put some thought into it and removed the end panels of the coil so the air could flow through. Sounds like a tech fresh out of school.