Found Reach-In Cooler evap coil iced up. evap fans working. condenser fan working. thawed ice with hot water. unit has condensate pump. so it took me a while to thaw ice because condensate pump could not drain quickly. checked defrost heaters. working fine. but unit did not come on. I found defrost timer not auto functioning. if I turn manually it works. I replaced defrost timer. turned unit on. tested defrost timer. defrost heaters working fine. fan delay is ok. sight glass was bubbling. I added r404a. pressures where they are supposed to be. temp dropping down.