TomTom GPS On/Off Switch Circuit Board Issue

Thread Starter

prdevoe

Joined Dec 21, 2016
5
The plastic button used to turn my older TomTom GPS (XL 340) on and off broke about a month ago and I was unable to find a replacement. I figured out that the plastic button which broke was used to push a small switch attached to the circuit board inside the GPS (see picture one). I started using a small toothpick to push on the switch to turn the GPS on and off and it worked for several weeks. Unfortunately, I pushed too hard with the toothpick and eventually broke the solder points of the switch to the circuit board and the switch detached from the board (see picture 2). I figure I could try to solder the switch back to the board but I am afraid that it will just break off again. Is there a way I can solder wire(s) to the board that I could simply touch the wires together to turn the unit on and/or off or is that not the way the switch and circuit interacted? Or can I somehow solder the board contact points in such a way that the GPS just turns on when I plug it into my cigarette lighter? I've included a picture of the back side of the board if it is needed. Thanks for any guidance anyone can provide.


IMG_E2392.JPG IMG_E2393.JPG IMG_E2394.JPG IMG_E2393.JPG
 

DickCappels

Joined Aug 21, 2008
6,962
Most likely a mechanical feature of the plastic button was limiting the travel and without that feature the full force of the toothpick was absorbed by the switch itself. The best solution would probably be to replace the plastic button.

Using some kind of continuity checker (ohmmeter, buzzer and battery, light bulb and battery, etc.) determine whether the switch is merely a single pole single throw switch or something more complicated. If it is single pole single throw then you can merely short the corresponding contacts on printed circuit board and see whether or not the GPS system turns on and off when you plug it into your lighter socket.

Alternatively, you can, as you suggest, run some small gauge wire from the switch contacts to a switch external to the GPS system. If you do that you might want to take the precautionary measure of making sure the connections are insulted from the outside world to reduce an unfortunate short circuit or electrostatic discharge.
 
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