Clock runs slow and does not keep accurate time. All other functions working.

If your cuckoo runs too fast or slow, the best way to correct this problem is to set your cuckoo to an accurate watch or clock. After 24 hours, record how many minutes your cuckoo is running too fast or slow. Then adjust the bob up or down the pendulum stick to change the pendulms effective length. You'll need to take an educated guess as to the distance. Reset the cuckoo minute hand time to your watch or clock again. Repeat this process every 24 hours, recording the results, and readjusting the bob until you are within 3 minutes of the correct time. Then, switch from recording every day to recording every week. Use the same process described, recording the time difference, adjusting the bob up or down every week, until the cuckoo is accurate within approximately 3 minutes per week. Remember, mechanical cuckoo clocks are not as accurate as quartz or electric clocks! A three minute error per week is not bad. Maybe you can do better. What you are attempting to do is to obtain is the best timekeeping possible from your cuckoo clock. Afterwards, you will still need to sychronize the cuckoo (coo coo) clock minute hand to an accurate clock or watch, each week or as desired.

Normally there is an adjustment available. /contact the manufacturer.

There are basically three types of electronic clock.
Quite old-fashioned are those that use the frequency of the mains electricity it is plugged into as a means of approximately keeping time. For practical purposes this type is more accurate than most mechanical types but may lose or gain a little and need adjusting from time-to-time.
If this type becomes unreliable there is nothing the user can do about it and an engineer would be needed or perhaps the garbage or recycling would be a better place.

The second type is the now very common quartz type where the clock circuitry keeps time by being triggered by a very accurate quartz crystal oscillator.
These types are generally so accurate it is worth providing battery back-up in case of power failure as well as preserving alarm and reminder settings.
If this type becomes inaccurate it indicates a problem with the circuitry and again recycling is probably the most practical option, though accumulated damp and dust inside can affect the delicate circuitry which might be restored to accuracy after a thorough internal clean.
I once had similar trouble with my clock radio which was caused in this instance by me forgetting how to operate it correctly. Spending a half-hour playing around with it refreshed my memory so in future I will remember when I have set the alarm to return the display to the clock.

The third type of clock is the radio controlled type that is set and keeps time by receiving a radio signal from a national atomic clock. They can do strange or unusual things if the signal is not being received properly or the clock is faulty but there is usually a function for setting the time manually though in my limited experience these aren't clocks for everyone and they aren't suitable for every location.
Good luck!

You have to adjust the bob on pendulum. If the clock is slow, the bob on the rod must be pushed up. If the clock is fast, the bob must be pushed down. Do adjustments bit by bit, day by day till the clock is keeping time. If all this does not work, you may need to replace suspension spring (if there is any). If there are no suspension spring, the clock may need proffessional attention.
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there may be a backup battery built in to this unit to keep the clock running in case the power goes out. depending on the age of the unit, it may need to be replaced. the battery size and number as well as it's location should be in the owner's manual.

Were you able to repair your clock ? I have the same 24" clock from Sam's Club and have given up on finding the Shontek DM2720 movement. Please let me know.

There are three buttons, let's call them 1, 2, and 3, from left to right.


Clock
Time setting

A. 12 AM, PM or 24.00 h
With the clock in the time readout mode, keep
button (2) depressed for 4 seconds -12 AM, PM
or 24.00 flashing. After pushing button (1), either
a 12-hour (AM + PM) or a 24-hour setting
program can be selected. If you only want to
change the display mode, push button (3). The
clock then returns to its normal timekeeping
function.

B. Hours
Push button (2) a second time - hour display
flashes. Set hour by pushing button (1). After
pushing button (3)*, the clock returns to the time
readout mode with new hour setting.

C. Minutes
Push button (2) once more - minute display
flashes. Set minute by pushing button (1). Upon
pushing button (3)*, the clock is started -
accurate to within 1 second.

Stop watch function
The stop watch can only be set in motion if the
clock is in its normal timekeeping mode and not
during setting operations.
A. Push button (3) - 00:00 display appears;
B. Push button (1) - stop watch is on;
C. Push button (1) a second time - watch stops.
(Additional times can be added by pushing button
(1) again - stop watch keeps running. Push button
(1) once more to stop timing.)
D. Push button (2) - 00:00 display appears;
E. Push button (3) - normal timekeeping mode.

If button (3) is pushed during operation A and
B, the setting procedure must be restarted
(push button (2)).

You have to adjust the bob on pendulum. If the clock is slow, the bob on the rod must be pushed up. If the clock is fast, the bob must be pushed down. Do adjustments bit by bit, day by day till the clock is keeping time. If all this does not work, you may need to replace suspension spring (if there is any). If there are no suspension spring, the clock may need proffessional attention.

This set will need service on its time-base circuit. It could be a crystal, or a bad processor...accordianman

This is a problem with the clocks tuning crystal. Digital clocks have a crystal that is tuned to run at a certain frequency to keep the clock working correctly. These clocks have a problem with that crystal keeping the frequency locked at the correct working frequency. This problem will sometimes cause the clocks to run fast due to a running frequency higher than the regulated frequency and sometime slow due to a running frequency running lower than the regulated frequency. The only way to fix this problem is to either adjust the crystals frequency to the correct frequency and lock it. Or change the crystal. Both these types of service require tools and test equipment to fix the problem. This is usually best handled by a service center. The Emerson customer support telephone number is 1-800-898-9020. Give them the make and model number of your clock radio and ask them for assistance. I hope this information helps you with your problem.