cuckoo clock

I would say you have a problem. I would check you lift lever and the strike lift cam or at least in that area. I would put it on a test stand and run it for several days that way you won’t have to keep taking it in and out of the case. One other thing to check is the lever that trips the music box. See if it is keeping it from tripping the strike. If it is hanging up your movement and keeping it from striking then on the test stand the movement alone should function properly. That way you will know if you have a movement or a music box problem or even a bellows problem. I always put my movements on a test stand to make sure it is functioning properly then I will put it in the case and just hook up the bellows. If it preforms properly then I will hook up the music box. I have always did this for the many years I have been fixing clocks. I have made many test stands for different clocks including cuckcoo clocks. Hope this helps Mark.