The most common wall clocks either run on a battery or are key-wound. Winding wall clocks have gears and cogs that turn together in conjunction with each other to keep proper time. Battery-powered clocks, which feature quartz technology, use electrical pulses to keep proper time. Basic troubleshooting steps vary by type, but they may resolve simple problems that cause such clocks to stop running, run too slow or too fast, or act erratically. Beyond the basic measures, however, repair of a clock requires the services of a professional.
Wind the clock if it has stopped running. You should hear a ticking sound. If not, there may be internal damage.
Swing the pendulum on the inside of the clock if it has a pendulum. Open the door and bring the pendulum all the way to the side, then let go.
Open the clock face and inspect the clock hands. If the clock hands are touching, that may be the reason the clock stopped moving. Push the hour hand back and forth gently to release it. Bend the hour or minute hand (whichever is on top) slightly toward you to create clearance.
Adjust the bob at the bottom of the pendulum if the clock is running too fast or slow. Push the bob up to make the clock run faster, and push the bob down to make it slower.
Check the batteries in the back of the clock for power. Replace the batteries if they are bad or corroded.
Replace the batteries if the clock is running slow or it rings erratically.
Set the time using the minute hand if it is running too fast or slow. Setting the clock by the hour hand may make it run erratically.
Open the back of the clock and inspect it for dust or debris. Remove any dust with a soft brush.