Hamilton 992- runs fine when watch is face down, stops running face up. Is this symptomatic of any other condition besides a problem with the balance staff?

Any help would be greatly appreciated.

Thanks

Very likely to be in the balance. The most likely culprit is a peened pivot in the balance staff. That can be dressed without being replaced. In fact, there is a type of collet that will hold a balance wheel WITH the hair spring stil on.

But it may be other things as well. It could be a damaged jewel or one that is the improper size. It could be due to excessive end-shake.

I would first take a look at the jewel under high magnification. Do you see any cracks?

Next, I'd look at the pivots under high (I mean really high) magnification. Peening looks like a little mushrooming at the end of the pivot. Sometimes it can be so bad that the pivot will not enter the jewel or might break the jewel when removed. Look also to see if there are wear-grooves on the pivots.

If everything looks good, I'd go ahead and set the balance and then check the balance wheel for excessive end-shake and side-shake (Careful! You can easily break the pivot doing this.)

If everything still is good, then I'd be scratching my head and wondering who the last butcher, to work on the watch, actually did with it.

There might be other causes. Something might be binding in the drive-train in that position or the mainspring barrel could bind (happens more frequently on those Illinois models with the 3-screws). But, the odds of that are much more remote than a balance problem.

Hope this helps.

Foster, In addition to the balance pivots and end stones, may also be worth checking the hairspring for 'coning' or being a touch lopsided. When face up, it could be hanging enough to catch the balance arms and stop the watch.

John

Thanks for the response- It actually is a 992E, in a BOC case that I was able to pick up for $250. Now I know why it was such a great deal!