I had much the same problem with my 1200. It could be a bad thermistor... the thing on the right fin in the refer. On my 1200 by pressing both the mode and temp buttons it will go into a diagnostic mode. Then the third press of the mode button will show the temp that the thermistor is reading. By putting it in cups of various temps of water you can check if it is working properly. By unhooking the thermistor is will make the unit go into max cooling. My thermistor was good and I ended up replacing the control board.
