this unit isn't cooling, compressor & fan running, evap fan running, coils were iced up defrosted & it's happening again. defrost? is this unit on a timer or adaptive defrost? anyone have a schematic?

Your defrost control is in the motherboard in the back. To manually force defrost, remove the motherboard cover, unplug fridg and locate the three pin power connector. Unplug it and match up the mating pins on the pc board labled Line and Defr. Put a wire jumper between the mating pins on the connector. Plug in fridg, it should now defrost. If not, you have a bad defrost heater.