York YHKMXH009BARX-FX, Service Manual, Page: 250 / 269

no
start
as per the wiring
diagram, check if
communication
wiring is correct
yes
yes
yes
no
no
re-wiring, and
check again
check if the
communication port
connecting to the
indoor/outdoor PCB is
in open circuit
if the power cable and the
communication wire are
too close, resulting in the
wrong commission data
PCB is faulty,
replace and
check again
replace the
communication
connection wire,
check again
adjust the
distance and
check again
Trouble 4: Indoor PCB EEPROM data is wrong
1.If the failure occurs when being electrified for the first time, that shows EEPROM
(
8-bit pin) not fixed firmly or
damaged.
2.If the failure occurs when running, that shows EEPROM is faulty and need to be replaced.
Trouble 5: Indoor repeated unit number
1.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 numbe r. By this method,you can check if there is repeated unit
number, 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 unit
with pipe C is No.3
Trouble 6: Indoor fan motor failure, AC fan motor has not 50Hz zero-crossing detection
start
check if the fan
motor input
connection is fixed
badly(CN3 on PCB)
no
no
yes
yes
check the fan motor
feedback wire is
fixed badly (CN23
on PCB)
PCB is faulty
and replace it
replace fan motor
input port, cut off
power supply and
be electrified again
replace fan motor
feedback port, cut off
power supply and be
electrified again
Trouble 7: Outdoor unit failure
Check the failure code on outdoor indicator board (5-lamp)
Trouble 3: Communication failure between indoor and outdoor
248