It is time to give the spring driven clocks clock a good cleaning and check it over for excessive wear. this section is for weight driven clocks westminster or other 15 minute melodies not chiming the hour, on the hour. if it bumps anything, even slightly, then it loses some momentum and the clock will eventually stop. if the manual clockwork stopped working clock is chiming prematurely only about 5 minutes or so before it is supposed to chime, on most clocks you can just take clockwork off the minute hand and turn the bushing that is in the center of the hand one way or another so stopped it is exactly on the hour when it bongs its melodies. manual if this is causing the cuckoo clock to stop, try pushing the hour hand toward the clock face to snap it back in to proper position, doing so will keep the hands from binding and free up the movement. for example, set the clock to 5 minutes before 12 to see if the pendulum stops working a minute or so after the cuckoo clock hands meet. this section is for weight driven clocks westminster or other 15 minute melodies not chiming the hour, on the hour. if these things do not fix the clock then it would be safe to assume there is a general lack of power in the time train.