Ronstan clear start regata startwatch repair

Last year i ordered one of those startwatches for my son. He is racing in Optimist sailboat, and startwatch makes starting much easier. Price for it is about 50-60euro, quite high for a plastic watch. But it is made for sailing, so the price has to be high. I was thinking to make it by myself based on msp430 microcontroller, but the problem is how to make such device waterproof.

As it turned out later, even Ronstan (or their chinese outsourcers) has a problem to make it work.

One of my coleagues was on a business trip to Canada, and to save some money, we asked him to bring us this watch. My son collected money with his work, but i still had to participate 50%.

Boy was very happy with the new startwatch, it realy has everithing what is needed for young sailor. But it did'nt last long... after third training, when he capsized, the watch died.

The seal under the cover was badly placed during the production, so the water entered the case. I opened it, washed it with fresh water and when it was dry, it started to work again.

After winter the new season begun, and there was important opti race. After second day, the watch died again. The trainer went to some local watch service to change the battery, but the cause was not battery...

When the boy was back home, i immediately started service. I opened the case, and i found out that if i shake or touch a watch at the certain point it starts to work.

From my hamradio and homebrow projects i remember the hint from s53mv that quartz crystals are fragile and tend to brake. So it was the 32.768KHz crystal, which you can find in almost every quartz clock and also on PC boards that was major suspect.

In any home (especialy homebrewers) there is usualy enough broken or unused, ready for canibalisation objects. So i found a “made in china” promotional watch and took the crystal out.

After i replaced the crystal the stopwatch worked again

There is more to be done on this stopwatch. The plastic buckle on the strap is broken,

My son says, all of his sailing colleagues have the same problem with this type of watch.

This problem is still to be solved...