Power Reserve Issue, Service requirement

[TomWhitson]

I have a GMT II which is 3.5 years old and has recently started to stop, which I believe is relatively normal (I do not wear the watch at night and I work at a desk). I decided to test the power reserve (winding 40 full turns and leaving overnight) and found that it was lasting around 12 hours.

I sent the watch for service (at the UAE authorised service center) with a note that the power reserve seemed faulty and they have advidsed that due to dry oils the movement has low amplitude (no figure given) which is causing the power reserve to not fully charge. They have not mentioned any issue with the main spring nor given an indication of the power reserve function.

From what I have read I am not sure what they are saying makes sense. I understood that amplitude is more to do with the speed of the watch and that normally issues with power reserve are related to the mainspring. Is my basic knowledge correct? As for the dry oil, I assume this could be causing any number of issues (they have not indicated which areas are dry)?

They are asking to do a full service (which as I understand will roughly involve replacing quite a few parts main spring included, re-oiling, testing and re-sealing) I am a bit unsure wether to go ahead given what they have told me. It seems their idea is to do a service regardless of any issues in hopes that the service will just make the watch as good as new.

I've not got a particular issue in getting the watch services, I would just like to ensure it is done properly and for the right reasons (not a fan of fixing things that aren't broken). My current inclination is to get the watch back and re-test it a bit more myself, then if needed take it to a RSC when I am back in the UK next.

Thanks for any input!