Reasons your Cuckoo may stop working

Below is a list of common reasons Cuckoo Clocks stop working, some are easy fixes and others will be service related

Common Cuckoo problems

Out of Beat: The clock is tilted slightly to one side, causing an uneven "tick...tock" rhythm instead of a symmetrical, steady beat.
Air Currents: Ceiling fans, air conditioning vents, or open doors create a breeze that halts the lightweight pendulum.
Wall Contact: The clock case is shifting or not resting flat against the wall, causing the pendulum or weights to rub against the case.

Unwound Weights: The heavy iron weights have reached the floor or a piece of furniture, removing the gravity-driven power source.
Knot or Jam in Chains: The chain links have twisted, caught on a piece of internal wood, or jumped off the internal sprocket gear.
Winding Interruptions: Pulling the chains too aggressively relieves the driving force from the gears temporarily, which halts the pendulum mid-swing.

Interlocking Hands: The hour hand and minute hand are bent or loose, causing them to physically catch or rub against each other.
Dial Contact: The hour hand is pressed too firmly against the clock face, creating friction that stops the gear train.
Pre-Chime Jam: The minute hand stops moving entirely around the 55-to-58-minute mark because the internal warning lever has jammed before the cuckoo triggers.

Dried Oil and Grime: Microscopic dust, pet dander, or old lubricants turn into a sticky paste inside the pivot holes, creating too much friction for the weights to overcome. [
Worn Pivot Bushings: Decades of friction turn the perfectly round gear-shaft holes into oval shapes, causing gears to bind up and lose power.
Bent Escapement Teeth: The escape wheel or the pallet mechanism that interacts with the pendulum has been physically bent during transport or aggressive hand setting.

Silent Switch Activation: The shut-off lever on the side or bottom of the case is half-engaged, jamming the release lever.
Trapped Cuckoo Bird: The cuckoo door latch is closed, or the door hinges are warped, preventing the bird from swinging forward and stalling the strike train.
Lifting Wire Jam: The internal wires that lift the bellows or open the door have become tangled, bent, or caught on the wooden frame.

Trapped Cuckoo bird in bellows

Bushings badly worn allowing excess movement of Pivots

Dirt build up and incorrect oils used