Haier 1U50REJFRA Service Manual

Service diagnosis40 Domestic air conditioner10.3.7 The communication fault between IPM and outdoor PCBOutdoor display: ƵƾƵ)03LED1 flash 4timesMethod of Communication is detected by checking the IPM module and the outdoor PCBMalfunctionDetectionMalfunction ■ The outdoor PCB broken leads to communication faultDecision ■ The IPM module broken leads to communication faultConditionsSupposed ■ The outdoor PCB is brokenCauses ■ The IPM module is broken■ Communication wiring disconnectedTroubleshooting * Caution Be sure to turn off power switch before connect or disconnect connector, or elseparts damage may be occurred.1) Check whether Terminal CN23 and CN24 on the outdoor mainboardCN10 and CN11 on IPM module2) Check whether the connected wire between IPM and outdoorAre they good?Electrify the machine again and turn iton, Check whether the voltage between1 and 2 of Terminal CN23 is about DC5V,Check whether the voltage between2and 3 of Terminal CN23 is about DC15V,Replace the outdoor mainboard with a new oneReplace the outdoor IPM modulewith a new one.YESNONOYESMalfunction unsolved1) Pull out and reinsert the terminals.2) Replace connected wire