If you do not have a measuring tool, such as a pressure gauge, it will be difficult for you to find the problem. But most likely it lacks refrigerant. At first glance, when we turn on the equipment, some of the pipes freezes, which is a sign that it lacks refrigerant. But be careful, if after a few minutes this does not happen, it is because you lack the total refrigerant. The solution: pressurize with nitrogen to locate the leak, repair it, vacuum the entire circuit (including the condenser) and recharge refrigerant. I hope my answer serves you, good luck! Best regards