If your watch is not resetting to zero do the following. No tools needed. Works on most quartz chrono.
It is a very easy fix.
See the pic here. There are two pushers and a crown. There is a pusher at 2 o'clock and one at 4 o'clock.
1. Pull the crown.
2. Press on pusher at 4. Keep pushing it till it goes to zero. It should move in one second increments.
3. Once you are on desired marker, leave everything alone.
4. Push the crown back in.
5. It should be fixed.
6. Enjoy your quartz. If it is a rep that is suppose to be auto and it is quartz, don't use chrono in front of your friends. It is a dead giveaway.
It is a very easy fix.

See the pic here. There are two pushers and a crown. There is a pusher at 2 o'clock and one at 4 o'clock.
1. Pull the crown.
2. Press on pusher at 4. Keep pushing it till it goes to zero. It should move in one second increments.
3. Once you are on desired marker, leave everything alone.
4. Push the crown back in.
5. It should be fixed.
6. Enjoy your quartz. If it is a rep that is suppose to be auto and it is quartz, don't use chrono in front of your friends. It is a dead giveaway.