Watchmaking: Servicing a PAM 196

I was recently sent a PAM 196 for servicing and I thought I would share this servicing with you guys here, so here it is.

Before opening the case, I did a few checks and one was putting it on my timing machine. I noted a problem right away in that the balance amplitude was dropping off very quickly. Here I place the watch dial up on the machine, and the balance amplitude is 292 degrees, so well within the range where it should be:



But here some 10 minutes later, it had dropped off substantially to the 230 degree range. Normally this would take well over 24 hours for this sort of drop, so the watch was not being properly powered:



So it was time to dig in and give the movement a complete overhaul. Here the case back is off and you can see the ETA/Valjoux 7753 movement that powers this model:



Now taking the crown lever off to remove the crown and get the movement out:



Here the movement is out and I'm ready to remove the hands:



This is the movement spacer that also has extensions for the pushers:



So here are a few steps during the process of disassembling the movement (not all steps shown of course). First the dial side:









Now the other side:





Now with most of the chronograph parts off, I'm down to the base movement here:





Here are all the parts in storage trays sorted by their function:



Now some parts in the cleaning baskets ready for the cleaning machine:



Here the baskets are mounted in the cleaning machine and from here the cleaning cycle is all automatic:



With the cleaning done I'm ready to start aseembling the movement.

Here the balance jewels have been lubricated, and I'm making adjustments to the flatness and centering of the balance spring:



Of course a new mainspring is installed as part of the servicing:



Here the base movement is almost back together:



Here is a photo of the pallet fork jewel that I will apply the lubrication to. The surface I will lubricate is the small rectangle at the end of the red arrow:



With the base movement assembled, I perform checks on it's function before going any further:



Here you can see the delta (at the red arrow) which is the variation over 6 positions:



Back to assembling the movement:





Here using the microscope to check some adjustments on the chronograph:



With that done, now back to the dial side for more assembly:







With all the chronograph and quickset date functions working properly, I mount the dial and the hands:



The owner requested that I polish the bezel on this watch so here I have masked it off for polishing using polyamide tape:



With that done, the movement is placed back in the case:



The oscillating weight is fitted:



New gaskets are fitted and the watch is now cased:



Here the watch is going through one of several extended timing checks, and this one is on the final test winder:



And here the watch is in the dry pressure testing machine, and the diver program is selected that will test it in two phases. Phase 1 is a -0.7 Bar vacuum, and Phase 2 is a +10 Bar pressure:



And here the results are in, and the case passed the testing with no problems:



The watch is already back on the wrist of it's owner. Hope you enjoyed seeing how this servicing was done.

Cheers, Al