York YHKMXH009BARX-FX Service Manual

nostartas per the wiringdiagram, check ifcommunicationwiring is correctyesyes yesno nore-wiring, andcheck againcheck if thecommunication portconnecting to theindoor/outdoor PCB isin open circuitif the power cable and thecommunication wire aretoo close, resulting in thewrong commission dataPCB is faulty,replace andcheck againreplace thecommunicationconnection wire,check againadjust thedistance andcheck againTrouble 4: Indoor PCB EEPROM data is wrong1.If the failure occurs when being electrified for the first time, that shows EEPROM (8-bit pin) not fixed firmly ordamaged.2.If the failure occurs when running, thatshows EEPROM is faulty and need to be replaced.Trouble 5: Indoor repeated unit number1.Firstly query the unit number: switch off the unit, press SLEEP for about 15 seconds until the buzzer sounds 5 times,on the display panel there will be digit, which is indoor number. By this method,you can check if there is repeated unitnumber, if yes, please re-set the number as per the unit number setting procedure.2.Re-set the unit number directly, the unit with outdoor pipe A is No. 1; the unit with outdoor pipe B is No. 2; the unitwith pipe C is No.3Trouble 6: Indoor fan motor failure, AC fan motor has not 50Hz zero-crossing detectionstartcheck if the fanmotor inputconnection is fixedbadly(CN3 on PCB)no noyes yescheck the fan motorfeedback wire isfixed badly (CN23on PCB)PCB is faultyand replace itreplace fan motorinput port, cut offpower supply andbe electrified againreplace fan motorfeedback port, cut offpower supply and beelectrified againTrouble 7: Outdoor unit failureCheck the failure code on outdoor indicator board (5-lamp)Trouble 3: Communication failure between indoor and outdoor248