Midea MFA-96CRN1 Technical Manual page 54

R410A 50Hz Tropical Split AC
Operation lamp flashes:
All lamps flashing at 5Hz
Judge 1: The PRO terminal on PCB of indoor unit without connecting to grounding wire
Validate: Check whether the PRO terminal on PCB of indoor
unit without connected to grounding wire.
Judge 2: Optical coupler on PCB malfunction
Validate: Check whether the Optical coupler is normal.
Replace indoor PCB.
54
Yes
Yes
MCAC-UTSM-2012-12
No
Connect it to grounding wire.
No
Replace optical coupler