AC Diagnostic System: Kitchen unit Refrigerant Type R410A Metering Device- TXV Circuit 1 SP/HP 126/368 VSAT/LSAT 43/110 Circuit 2 SP/HP 142/421 VSAT/LSAT 49/120 Outdoor Entering Air Temperature 90 Notes: Kitchen unit was not cooling, manager showed me the thermostat was blank. I went onto the roof and found the smoke detector was shutting down the system. After resting the smoke detector the system came on a made a loud screeching sound from the blower compartment. I opened blower section and the shaving of the belt where all over the place and the belt was slipping making the screeching sound. The belt rubbing on the pulley could have been producing smoke with set off the smoke detector. System is currently operating with work out belt. We have placed a new belt on order will be returning to replace belt.