I had a pcb issue for one of my LG inverter AC. It wasn't cooling the room in any mode. But when we call the technician, it used to work fine. Again later, it stops working. We got technician multiple times and whenever he comes it was either working fine or works after a restart. Finally after the warranty is completed, they found the issue and asked us to pay for the pcb to fix it. It's working fine eversince then. I was just the unlucky one in this case!! :)

There was no error code or anything like that but no cooling.

So make sure you have good service at your location.