When clocks don’t work, we’re late for something. This Fix-It Guide on electric clock repair tells how an electric clock works, what often goes wrong, how to identify an electric clock problem, and what parts and tools you will need to fix it. It then gives simple step-by-step instructions for how to disassemble an electric clock and how to repair an analog alarm clock mechanism that doesn’t ring on time, and how to repair an analog alarm clock mechanism that doesn’t ring at all. This Fix-It Guide also refers to electrical cord repair and motor repair for specific problems.
How Does an Electric Clock Work?
A clock is an instrument for measuring time. Electric clocks rely on the 60-cycle-per-second alternations of household current (AC) to ensure accurate timekeeping.
A synchronous motor inside an analog clock drives a gear train, which in turn moves the clock’s hands. Older clocks may have metal gears, but the gears of new clocks are generally made of plastic to reduce operating noise–and manufacturing costs.
When an alarm is set on an analog clock, a cam gear presses against a lever, which in turn holds a vibrator arm above a frame. At the preset time, the cam gear moves outward, allowing the vibrator arm to repeatedly contact, or buzz, the frame.
Digital clocks rely on electronic circuitry instead of gears and levers. If a component fails, however, the clock will probably have to be replaced because most are difficult to repair.
What Can Go Wrong with an Electric Clock?
So why won’t your electric clock work? On analog clocks, hands can work loose, gear teeth can wear down or break, the clock may not run at all or may keep time poorly, or the clock can be noisy. On digital clocks, the cord or battery may not deliver power to the motor.
With an inexpensive clock, it may not be worth your time to attempt repair. But before tossing the entire clock, check a local craft or electronic shop for a replacement digital clock mechanism.
How Can I Identify an Electric Clock Problem?
If you’re late for work, maybe you can blame–and fix–the clock. Here are some typical problems:
- If the hands work loose, use pliers to squeeze the hands tighter to the central shaft.
- If the clock does not run, make sure that the power is on at the outlet and test the electrical cord.
- If the clock still does not run or keeps time poorly, disassemble the clock (see below) and remove any dirt or lint obstructing the motor or gears. Also, use a multimeter to test the field coil inside the clock. Check the gears for wear; replace the clock if the gears are damaged or worn beyond use.
- If the clock is noisy, check for loose parts or a dry shaft. Secure a rattling crystal with a drop of clear silicone adhesive. Tighten motor mounting screws. Apply a drop of light oil at the point where the motor shaft exits the housing.
Always remember to unplug the clock before disassembling and working on it.
What Do I Need for Electric Clock Repair?
You can find replacement parts from the manufacturer or through aftermarket suppliers. In addition, you can find digital clock units at larger craft stores. The tools you’ll need to fix an electric clock include these:
- Electric contact cleaner
What Are the Steps to Electric Clock Repair?
Disassemble an electric clock:
- Unplug the clock from the electrical outlet.
- Carefully pry off the face cover with a knife blade.
- Remove the screws from the case and slide the motor and gears out.
- If necessary, de-solder the power cord leads from the field coil terminals to remove the cord.
Repair an analog alarm clock mechanism that sounds at the wrong time:
- Pull the alarm lever out and turn the clock hands until the alarm goes off
- Unplug the clock and pry off the crystal.
- Move the alarm hand until it agrees with the time the alarm sounds.
Repair an analog alarm clock mechanism that doesn’t ring at all:
- Access the alarm mechanism.
- Spray the alarm mechanism with electrical contact cleaner.
- Clean the vibrator arm.
- Carefully bend the vibrator arm to adjust the gap between the arm and frame as needed.
If you have an older clock that you like but can’t repair, consider replacing the mechanism with an inexpensive digital clock mechanism.