Hi Richard

My crane is a 46715 same as yours in yellow

Here are 2 pictures of the inside


Likely your problem is mechanical
Cheers

Jean

Hi Richard and forum friends

According to the Stummi forum (one of Germany's largest on trains) it appears that Märklin does not support the models including Piezo motors anymore
I have 2 models having piezo motors: the first "Turmtriebwagen" (Catenary work rail car) 39970 and the crane 46715.
I had to repair the "Turmtriebwagen" because the pantograph was not moving. It turned out that the nose of the Piezzo motor (in contact with the rotating wheel) was worn out. You may see it in action after repair in this videohttps://www.youtube.com/watch?v=bAlsyI-uALY&t=173s
I repaired it by filing off a section of the nose, make a part shaped to finish the nose (to replace the missing part) and made of aluminum. Glued with Cyanoacrilate. It works.
My crane 46715 is fully functional but the cabin rotation is very painful (sometimes it does not rotate in one direction). I have not repaired it yet but I will soon check what is the matter with it. Of course the decoder may die but this is not usually the case (unless by external electrical shock)
The company which makes the motors is still in business: Thorlabs and the motor is Elliptec™
Look here https://www.thorlabs.com/newgrou...cfm?objectgroup_id=10122 at the page's bottom
I don't know what your crane has but IMO the 2 best suspects are : fast erosion of the motor nose (very soft aluminum) or mechanical resistance (the motors are not powerfull (to say the least) so any resistance will stop it.
To know if the motor is vibrating, simply touch it (gently) while it is supposed to run. You will feel vibrations

Cheers
Jean

Hi
As Dale said reset is usually done by writing 8 into CV8

Cheers

Jean