DIAGNOSIS Refrigerant is not circulating. Most likely cause is a kinked or crushed refrigerant line from mishandling.
FIX Inspect the entire length of the exhaust hose assembly. Look for sharp bends or crushing, especially where it connects to the window bracket. Straighten any kinks. Ensure the hose is fully extended, not compressed.
IF THAT DIDN'T WORK The system may have developed a leak. Listen for a faint hissing sound near the compressor area. If you hear it, the unit has lost its refrigerant charge. This requires professional repair.
HEADS UP Never transport or store the unit on its side or back for extended periods. Always keep it upright to prevent oil migration and potential line damage.