No AC back unit board has failed, not putting voltage out to turn blower on. Wired blower hot, thawed coil, checked charge. Will return early next week with new board and will do check ups on all 3 units 6/10/2024 returned and replaced control board on back furnace, rewired to run normally, tested operation, system is cooling. Performed maintenance on all 3 units, washed condensers, inspected all electrical, replaced completely dead capacitor for back unit condenser, added 2 lb r22 to hallway condenser, replaced thermostat in lobby, has been malfunctioning on a regular basis per management. All systems had fresh looking filters so I did not change them