If you have the same symptom with your aircon, you can checking their manual, and find that blinking 5 times means there is a problem with the outdoor condenser unit (model MSY-GE24VA).
My aircon was out-of-warranty, but I still called the serviceman hoping the repair/replacement won’t be a huge price tag.
TIP: Save yourself $60 and don’t get the serviceman to come check, as eventually they will quote $770 to replace (at least for this model). A new model will be $1,800 but provides another 5y warranty for the condenser.
A very common issue with the PCB board
Many people have the same problem. If a small chip on the board is fried, the whole board becomes useless.
What’s even crazier is my NEW replacement aircon came, installed, yet it is NOT working! 😡
Took them a few days to come service it.. and turns out the indoor fan coil board is spoilt.
The quality of Mitsubishi is very disappointing.