According to the "manual" key, when the phone is switched on indoor machine fan is operating normally, 3 minutes after the machine stops working all; Press "mandatory", when the phone is switched on indoor machine fan jitter two times after a halt (mandatory start compressor 3 minutes without delay. When measuring CPU 18 feet, when the compressor terminals output signal of the CPU, the foot voltage of 3.2 V (normal should jump to 0 V to 5 V), when the load off the foot, back to 5 V voltage normal, and no longer appear downtime phenomenon, fault point is clearly here. Replace UN4211 band-stop triode, troubleshooting.xyXservice manual download site