Have you let it run down (or unwound the mainspring under control)? If not, do that first.
Then remove the balance and pallet.
Give the mainspring a wind (just a few turns) and see if the train runs without hinderance.
Ideally, you should get a little backlash/backrun in the train right at the end as the mainspring recoils.
Let's know how that goes.
Can be a loose pallet, bent banking stop, bent pivot, bent hairspring, balance and hairspring touching, ... also if the staff was changed there is quite often a loose paper shim under the bridge if the staff height was wrong. If there was and you discarded it, it won't run so you may have to put the balance without pallet to check if it goes smoothly. Also double check the balance jewels.
Please describe your cleaning process. Fluids used, equipment?
Does the mainspring barrel move freely. It could be in a bind. You should be able to get the watch to run with the mainspring down and apply a little bit of torque (in the proper direction, of course).
Have you had success with that ultrasonic machine in cleaning watches? Have you had success with that leaning solution for cleaning watches? Have you checked the jewelled bearings for cleanliness after your cleaning procedure? Gummed lubricants can be stubborn to remove if you use a cleaner and a solution which is not up to the job.
The ultrasonic machine shown in your post has roughly half the cleaning power of an ultrasonic machine designed for the purpose. Gummed oil can still contaminate the pivots, even if the jewels appear to be clean. Pithwood can be used to mechanically remove contaminates from the pivots.
Something I missed earlier. Notice the 4 little marks aligned under the balance cock? This kind of small dimples were usually punched in the metal after a balance staff repair, to get more clearance for the balance if somehow the staff is too high (same purpose as adding a paper shim between cock and baseplate). Something was done here at some point.
This may sound silly, but finding out what the problem IS involves find out what the problem ISN鈥橳, by a process of elimination. Take the pallets and pallet bridge out, then put the balance wheel and balance cock back in, and test the balance for freedom. Test it for freedom face up, and face down. Check the balance for end shake. Test freedom of the balance wheel FACE UP and FACE DOWN. Is the hairspring cupped UP and rubbing on the balance cock? Is the hairspring cupped DOWN and dragging on the balance arms? Is it canted toward the centre wheel, the outer coil dragging on the centre wheel. Has a screw on the rim of the balance loosened and the screw dragging either on the recess in the pillar plate for the balance wheel, or on the heel of the balance cock? Has the roller table loosened, dropped on the staff, now rubbing on the pallet fork. Or perhaps rubbing on the pillar plate. Troubleshooting a watch isn鈥檛 neurosurgery. It just means you need to think about the process, one step at a time.
