Midea MSH-07CRN1, MSH-07HRN1, MSH-09CRN1, MSH-09HRN1, MSH-12CRN1, MSH-12HRN1 - Page 300

11.1.2
Display LED STATUS
E1 Indoor / outdoor units communication protection
Is the LED in outdoor main PCB light?
Is the +5 voltage in outdoor main board?
Outdoor main PCB: CN5 between No7(Blue) and
No8(Yellow)
Main chip(ADMCF328): between No10 and No19
Check the PC817,PC851 (indoor PCB and Outdoor main PCB)
Yes
Is PC817 or PC851 normal?
Yes
1. check the signal wire between, is it
connected good.
2. replace the PCB of indoor unit ,is the
unit ok?
3. replace the PCB of power suppl
y
board ,is the unit ok?
4
No
Yes
No
Inverter module defective.
Rectifier defective
If PC817 or PC851 are defective, change indoor PCB or outdoor power PCB .
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