Manager said back half of store isn't cooling. Found rtu1 (dining area) with a bad compressor on circuit 2 and circuit 1 was a little low on 410a refrigerant. Circuit 2 may be low as well. Hot gas line appears to have been repaired multiple times. Found screw wedged in contactor to keep circuit 2 compressor running. Need to replace compressor, do leak search on both circuits, and clean condensing coil. Once repairs are done will be able to troubleshoot system further. Rtu 2 (kitchen/dining) circuit 1 is running but circuit 2 is empty of 410a. Need to pressure system with nitrogen and find leak(s). Compressor ohmed out ok but don't know if circuit has any other issues. Once leak is found/repaired will be able to troubleshoot further. Rtu3 transformer was tripped. Reset transformer and ran system through cooling cycle, checked amps, checked refrigerant charge, and checked for any low voltage shorts. Unit ran through cooling and transformer never tripped out. Rtu3 is cooling at this ti