When the HVAC technician arrived, the evaporator coil was frozen over. The indoor blower wasn't working but the blower run capacitor was okay. When the power was restored, the blower turned on. The technician repeated the power cycle to ensure that the blower would turn on when necessary. System is back up and cooling after our technician defrosted a coil and determined that the refrigerant pressures were within specifications. The technician said that if the problem reappears, we would probably need to replace the blower relay board.