Air Conditioner Service Manual
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terminal L and N (before display of E0 fault). If the voltage is
“0”, please replace indoor main PCB.
2) If the 1 & N which connect to indoor unit voltage is normal, measure the voltage between the outdoor
terminal 1A, 1B, 1C, 1D and N. If the voltage change occurs between 0~24V (change pulse voltage),
please replace indoor main PCB.
3) If the 1A, 1B, 1C, 1D & N which connect to indoor unit voltage is normal, measure the voltage between
the outdoor terminal 1 and N. If the voltage change occurs between 0~12V( change pulse voltage), but
there is no 24V, please replace the outdoor PCB.
4) If the 1, 1A, 1B, 1C, 1D & N voltage is normal, measure the voltage between the outdoor terminal 1
and N. If the voltage has no change, firstly replace the indoor main PCB. If the fault remains
unsolved, replace the outdoor PCB.
5) Communication fault if resistance or optical coupler broken, replace outdoor PCB.
Is there any burnt on PCB? If no, test the rectifier, FRD, IGBT etc. any component broken, replace PCB.
Communication
circuit