Haier H-MRV Series Service Manual page 189

Check if the sensor is properly
connected to the mainboard.
No
Reconnect
4.
Models with wired controller
Readout: E5
Description: Transmission error between indoor unit 846 chip and 808 chip.
What to do: Replace the mainboard.
5.
Models with wired controller
Readout: E7
Description: Transmission error with electronic expansion valve driver.
Check if the electric control of
indoor unit and the electric
control of expansion valve share
the same supply and if live wire
and null wire are properly
connected.
Yes
Check if the internal wiring of indoor unit and
expansion valve is properly done. For AE-
FCBKA mainboard, a jumper wire is used to
select the function of wire controller.
Yes
Check if the mainboard is noticeably damaged
and if the control panel works properly after
replacement.
Check if the PCB CN23 of AC series is short
connected.
Check the sensor resistance
Yes
with a multimeter:
R25 =10KΩ+3%
℃
B(25/50)=3741K+70K
Replace the sensor
Models with wireless remote controller
6 flashes of Timer light.
Models with wireless remote controller
5 flashes of Timer light.
No
Reconnect
Replace the
No
mainboard
Yes
Remove the
short wire
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Yes
Replace the mainboard.
；
No