New Explorer 2 doesn't always start when pushing crown in.

[richard371]

My father has a 2 month old Explorer 2 he purchased new from an AD recently when setting the time (seconds hack) and pushing in the crown the watch will sometimes not start unless you shake it a bit. The watch is fully wound 40X or so. Sometimes you can pull out the crown and push it an and it starts fine other times it wont start unless you give it a good shake. Should he service the watch and is this a pretty easy fix? Anyone else exp this before?

Thanks