York YHKJXH012BAM--FX Service Manual page 127

Trouble 7: AC current over current protection or current transducer damaged, or compressor blocked
rotor, compressor great vibration, compressor abnormal startup, state detecting curcuit abnormal or
compressor damaged.
The former twice failure can be resumed automatically, if outdoor board occurs this failure always, and
can not be resumed for a long time, that shows:
1. Power module (SPDU) damaged, please replace the power module, then re-wiring as per the wiring
diagram (70% possibility)
2. Short circuit in power board results in the power module damaged (15％ possibility)
3. Damaged compressor results in this failure (10％ possibility)
4. Main control board is faulty, replace it (5％ possibility)
Trouble 10: High pressure failure
Reasons:
1. Over high system pressure results that the unit stop, and the compressor protection will work. The
failure can be resumed.
2. Pressure switch wire is not fixed well or in open circuit.
start
check if the connector
between pressure
switch and PCB is
fixed badly or damaged
yes
replace pressure switch
connector, shut off and
be electrified again,
re-check
check if the 2 straight
no
lugs on the pressure
switch are in good
condition
yes
replace pressure
switch connector, shut
off and be electrified
again, re-check
if outdoor fan
no
motor cannot
startup normally
in cooling mode
yes
check if the
outdoor motor
has power input
127
replace main
no
control board
and check again
replace outdoor
no
motor and check
again