ETA 2824 movement on hand just unwound all its power via rotor

[Norberto]

Hi, so I am wearing a watch I put together from new parts and movement is an ETA 2824 clone.

While watchong a movie with kids I felt a crazy vibration on my wrist.

I thought, " this is new, I didn't make an alarm watch".

Looking through the case back glass I watched as rotor spun until the movement stopped 

So is this something others have seen or can diagnose?

I am guessing the automatic winding has failed in some way when the mainspring is fully wound but it is a year old movement and barely used.

Thanks

 

 

 

 

[Nucejoe]

  Power discharge due to malfunction of the click or loose ratchet wheel screw.

You will be removing the auto device anyway, so why not clean it and epilame treat the reversers if you have the grease.