Your center weight runs the time, right weight chimes, left weight hour strike. Your chimes have stopped which trip the hour strike so neither weight falls. If your clock has been serviced in the last 5 years you need oil. If the clock has not been serviced in over 10 years you need a cleaning. Do not spray oil on movement. Search web for instructions if you want to oil it yourself. Call in a professional if you need to have it cleaned.
Stevens Clocks, April 2013