Watch suddenly running slow - Powermatic 80

Hello.  I have a Tissot with the Powermatic 80 movement and it was running fine until yesterday evening at around -2 seconds (average deviation in different positions is about -2 seconds per day).  I checked it before I went to bed and it was about 9 seconds off and checked it this morning and it's now -12 seconds.  Can anyone think of the reason for such a sudden change?  I ran a compass near it and it doesn't appear to be magnetized and I only did a bit of cooking and cleaning dishes yesterday evening so it wasn't exposed to any major shocks.  

I also have a Hamilton which was also running fine a few months ago and is also about -12 seconds slow per day as well, but can't point to the time it began to run slow.  

I will take them both to a watchmaker as out of warranty.  I tend to keep my mechanical watches away from any magnets and they have never been abused like being dropped or knocked off things.    

Has anyone had any similar experience with a sudden change in deviation? Thanks

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Difficult to say, as you mentioned the biggest problems for watches are magnetism and shocks. What is interesting, is that it happened to two watches at the same time. 

Maybe you should search the problem from the other side? Maybe it´s a problem with your timegrapher, wrong settings, to loud around while testing? 

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Michel

Difficult to say, as you mentioned the biggest problems for watches are magnetism and shocks. What is interesting, is that it happened to two watches at the same time. 

Maybe you should search the problem from the other side? Maybe it´s a problem with your timegrapher, wrong settings, to loud around while testing? 

Thanks.  Don't have a timegrapher just measuring it against phone app.  The Hamilton has been going slow for a while the Tissot just started last night.  

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Dzyknior

Thanks.  Don't have a timegrapher just measuring it against phone app.  The Hamilton has been going slow for a while the Tissot just started last night.  

I´m pretty sure, that the app is just not accurate. That´s way more logic, than two watches running slow over night.

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Michel

I´m pretty sure, that the app is just not accurate. That´s way more logic, than two watches running slow over night.

Thanks Michel.  No it's definitely the watches that have the issue as measure them against phone, mutli band 6 watch, computer etc.   Hamilton started running slow a few months ago and Tissot only yesterday after running ok all day.  I'll bring them to a watch maker soon.  

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Magnetized movements run very fast, not slow. It may have something to with how the watch was laid down at night, remember, crown up to speed up, and crown down to slow down. Unfortunately it is one of the few calibers enthusiasts such as ourselves can not regulate. If regulation is something that bothers you a lot, I strongly suggest you nuy a timegrapher

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watchalot

Magnetized movements run very fast, not slow. It may have something to with how the watch was laid down at night, remember, crown up to speed up, and crown down to slow down. Unfortunately it is one of the few calibers enthusiasts such as ourselves can not regulate. If regulation is something that bothers you a lot, I strongly suggest you nuy a timegrapher

Thanks.  I was wearing it all day and started to go slow in the evening when I was still wearing it and I left it crown up overnight and still slowing down.  I was just wondering why the time changed so suddenly in the evening, I didn't drop the watch or give it a bang.    

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Some watches run slower as the power reserve dwindles, especially those with long power reserves. Give it a full wind and check the accuracy again. If it's still slow then take it in for a service.