Customer described the problem as the AC not cooling efficiently and making unusual noises. Upon initial inspection, I observed that the unit was not cycling properly and there was a noticeable rattling sound coming from the compressor. After conducting a series of diagnostic tests, including checking the refrigerant levels, inspecting the condenser coils, and testing the electrical connections, the results indicated that the refrigerant level was low and the condenser coils were dirty. The repairs performed included recharging the refrigerant and cleaning the condenser coils, and I replaced the air filter (part number AF1234). Following the repair, my final observations were that the AC unit was cycling properly, the noise had been eliminated, and it was cooling efficiently.