Upon arrival found lobby unit not cooling. Checked RTU and found that someone had replaced the transformer and unplugged the compressors, found both compressor contactors were burnt up, found R wire from transformer wired directly to R terminal on control board. Unhooked R wire from transformer and turned system on, found that the compressor contactors were cutting in and out really fast, checked pressure switches and pressures and everything was good. found that the control board would receive 24v from transformer but not put out 24v between R&C. System has a bad control board. Also filters need to be changed out in both units. Repairs were approved will call carrier in the morning to check availability on control board. Upon arrival replaced both compressor contactors and primary control board. Replaced filters in both units. Turned system one and everything is now coming on properly. Noticed that pressures were acting low, found no liquid in refrigerant system. Added 5lbs to first