# Repairing my GPS watch.



## Chris Hobson (Mar 12, 2017)

A little under two years ago I bought a Tomtom GPS Multisport watch to help monitor my triathlon training. It covers running, cycling, swimming and treadmill training and I have found it to be really useful. After you have done your training you plug it into your computer and it automatically logs onto your personal account on the Tomtom website and records your distance, time and various stats and even gives you a little map of where you went. After I had had it for just over a year it died. I had become so dependent on it that I bought another one straight away. Getting my kit out of the locker at the gym the other day, I dragged the watch out and it fell on the tiled floor and broke the glass. It still worked but I couldn't use it for swimming in case it got water in it. Having drawn a blank on getting a new glass on the internet, I had resigned myself to going back to counting lengths at the swimming pool until I could afford to replace it. I then remembered that I still had the old one so I set about taking it apart to see if I could use the screen from that one. It turned out to be a fairly simple repair, the watch is held together by six tiny torx screws. once these are removed the front and rear halves of the watch can be separated. The little circuit board is held in with two more torx screws and this can be removed and transferred into the other case. The battery is in the rear half of the case and didn't need to be disturbed. I tried it out and everything worked but after I had been swimming the control button stopped working. Upon inspection it turned out that a tiny bit of moisture had worked its way inside. I dried it out with the corner of a piece of kitchen towel and tried again, this time applying some silicone grease to the seal. I've been for another swim this morning and everything appears to be working so I'm cautiously optimistic. It has occurred to me that the old one died after I had been swimming and that water getting in may have been the problem. If so, I might have been able to revive it by taking it apart, drying it out and re-sealing it with silicone grease.


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## Chris Hobson (Mar 13, 2017)

Update. My cautious optimism seems to have been too err, optimistic. I went for a swim this morning and a couple of hours later the watch started playing up. It has a four way control button which acts on four tiny micro-switches and some of these have started giving false signals to the watch and switching it to swim mode. While at work I have recorded about half a dozen of the most leisurely swims ever. Having gone home I have taken it apart yet again and have found no evidence of any water getting in. I'm wondering if some moisture is still in the switches from the previous time so I have left the thing in a warm place for about an hour before screwing it back together. I've now plugged it into the computer and deleted all the non swims that have been faithfully recorded for me. It is now fully charged and seems to be working correctly once again. Tomorrow, I'm planning on riding my bike to work for the first time this year, let's see how it copes with that.


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## Matt Cycle (Mar 13, 2017)

I'm no expert but I would imagine once the seal is broken then there is always the risk of water getting in.  I used to have a wind-up wristwatch which claimed to be waterproof but it also stated once the back was taken off the waterproofing was no longer guaranteed.  How the hell was the watch meant to be serviced without taking the back off?


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## Chris Hobson (Mar 15, 2017)

I have a Seiko Titanium watch that is water resistant to  200 meters. It had to be sent to a specialist watch repairer to have a new battery fitted. This was a little costly but I considered it worth it because it is such a good watch. Regarding the GPS watch, I haven't worn it for swimming since drying it out and it has been working fine so water must be the problem. I'm sure it must be possible to seal it again, after all it was sealed when it was first assembled. I have been searching in the garage for some Hylomar jointing compound that I used when I fixed my motorbike but couldn't find it. That is going to be the next thing that I try, I will just have to buy another tube.


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## Chris Hobson (Mar 18, 2017)

Next update. I bought some automotive jointing compound from the car accessory shop. This stuff is specifically stated to be waterproof and is also an adhesive. This meant that if I didn't get it to seal this time I probably wouldn't be able to take it apart again. I have carefully removed all the silicone grease with a corner of kitchen towel soaked in glass cleaner and re-sealed it using the jointing compound which resembles bathroom sealant. It has now recorded bike rides, runs and swims and is working correctly except that now the little vibrator doesn't work. I think that I can live with that.


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## Chris Hobson (Mar 25, 2017)

Well, I've finally admitted defeat and ordered a new watch. I decided to get the same type as this gives me continuity on my training records. All the features have stopped working so that I now have the world's most expensive £5 digital watch. Basically it tells the time and the date but won't even upload information into the laptop.


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## Chris Hobson (Apr 28, 2017)

Update. My new Tomtom watch is slightly different from the old ones but works in more or less the same way. This one has a built in heart rate monitor and has settings for general gym workouts and cycling on the turbo trainer. It also has a fitbit type thing that counts your daily steps and gives you a little pendant if you reach ten thousand, which I do most days. The length counter for swimming is really accurate, the old one used to award the odd free length so I had never swum quite as far as it said I had. The latest update on the website has a feature that flags up PBs and awards you a little gold cup when you get one which I really like. So, although it was really unfortunate that I broke the old one, I really like the new one so I'm sort of happy.


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## Northerner (Apr 29, 2017)

You made a valiant attempt Chris!  My Garmin Forerunner 35 sounds a lot like your TomTom, features-wise  I've had it about 6 months now and I'm very happy with it, although I'm still a little dubious about the wrist-based heart-rate monitor.


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