I got a new microscope the other day and today I discovered something. Yesterday I coa'd a Rockford 16s. I used the scope to help me in assembley and got it together and it was running. Today I discovered it quit. I could see the balance worked fine but the fork was not moving.I dissembled the unit and looked at the Roller jewel and thought it was broke. I poped it off the staff and put it under the microscope and discovered that it was still there but on the wrong side of the table. I took a very fine needle like tool and touched it to the bottom of the table and the shellac had dissolved in the Ultra Sonic tank (Zenith cleaning fluid) and the roller jewel was about to fall through. The shellac looked like blobed glue.
Had it not been for the microscope I'd have lost that jewel because I didn't think it was there, I thought it was broken.
1 up for the use of a scope.
The punch line to this is What causes shellac to dissolve like that? It literately turned into some type of goo.

I don't see an answer to this dilemma yet, but maybe the last guy that worked on it didn't know shellac from Shinola!

Maybe the roller jewel was held in with super glue instead of shellac?

Patrick,

Every watch service should include a check of the roller jewel and pallet jewels since old shellac fails too. Now that you have a microscope you will be surprised how many loose jewels you find. Especially roller jewels. They might not be loose to the point of falling out, but loose enough to rock back and forth with the pallet fork action and since we are dealing with very little power to send the balance on its way, ANY movement of the roller jewel translates into less amplitude and maybe other problems as well. Glad you are enjoying using your new scope.