I also encountered this problem. Only I know about air conditioners. I lubricated the fan bearings so the unit would run quietly and without noise. Checked the thermostats and controls on the team. Cleaned the pipes, fan impeller, and drain trays with the proper chemicals. Also, cleaned the fan evaporator coil to ensure uninterrupted heat transfer without accumulation of dust and dirt. Replaced faulty bearings and eliminated production noise. But as it turned out, that wasn't enough. So I suggest you go to https://www.airconservicingsingapore.com/. I contacted them, and they explained to me that I had handled the problem myself.