Garmin GSC10 problems
Garmin GSC10 cadence sensor
The otherwise excellent Garmin 705 is let down by the GSC10 speed and cadence sensor. This unit is not properly waterproofed and eventually fails completely. You can revive it once or twice by drying it out but once water ingress causes corrosion or electronic failure the cadence sensor becomes a piece of junk.
It is mystifying to me why Garmin do not correct this problem. The solution is to properly waterproof the unit, surely that cannot be beyond the capabilities of this technologically sophisticated company?
I bought two cadence sensors with the 705 about 18 months ago. They started to fail after a couple of months. I had both replaced twice over the warranty period and now only have one working (which is on a bike used only on a turbo so it never gets wet).
There are quite a few posts on the forums at motionbased including one that describes how to fix the problem although you would need to be fairly skilled electronics engineer to follow the steps, it is way beyond me. A small sample of this solution reads:
It is a 100nF ceramic cap in 0402 (4mm x 2mm) case size. I replaced it with a 0603 size part which will fit ok on the pads. To do this you will need an smt iron and a stereo microscope, and a steady hand.
Note: The post at Motionbased has been removed by Garmin so it is no longer available, sorry.
What really irritates me is that Garmin are aware of the problem but they do nothing to fix it, and they keep on giving advice to people which just wastes their time. Once these things fail no amount of changing batteries and moving them away from each other will fix them. Get a new replacement GSC10 and it works immediately with no faffing about, proving the problem is with the unit rather than with incorrect user set-up.
The Garmin website claims the GSC10 has water resistance of IPX7, an IPX7 designation means the unit can withstand accidental immersion in one meter of water for up to 30 minutes. In my experience wash your bike a few times and the GSC10 will stop working. You can dry it out and get it working again once or twice but then it will be dead and cannot be revived again.
See also MACRO 2SXcom speed and cadence sensor
Lost the battery cover on the GSC 10 while riding. Garmin won’t sell a replacement. Anyone have a dead one they can sell me the cover?
Does anyone have the original text for the repair mentioned above, seems Garmin have removed the post detailing it from the web!
No sorry do not have the complete text, not sure what Garmin have done but no links appear to be working with the Motionbased forums.
didnt know the problem, and it happened to me after riding under a steady storm. . . poor disgrace!!! how to fix it??
i had the same issue with mine. I took it apart and the circuit board had corrosion on it. I cleaned the board and it still didnt work so I’m guessing one of the components didnt survive.
What I did discover is where I think the water is coming from. I took the small sensor arm screw off and noticed a large hole that the two wires go through into the main body of the unit. This is not sealed at all. Water will definitely get in from here.
So now on to the fix. I ordered a new sensor and will place silicone sealant into that hole along with some on the mounting screw for the arm.
If Garmin would conformal coat the PCB then this problem wouldnt exist.
Same problem here, the thing is a joke. I know two other people who’ve had the same issue with the GSC-10 failing like this, and funnily enough that’s everyone i know with the device!
Mine stopped after about 2 months, and it only saw a bit of light rain. The 705 on the other hand is great once you get over the quirks.
Absolutely agree about the waterproofing. If I ride in rain or if the road is particularly wet and spray is flying about, the GSC10 just works intermittently and then randomly stops working. I’ve replaced 2 in the last 18 months, was starting to think they’d got built in obsolescence, but having read this it now all makes sense. I will attempt to block the hole after some heavy drying out. As soon as you buy a new one it just works immediately. If anyone finds the solution posted anywhere I would love to revive my 2 ruined ones.
Argh – Garmin has just stopped registering speed on a turbo trainer (unit had done 12,000 miles outside before bike was moved to turbo). After getting no where with Garmin for fault finding (apart from its broken) I took it apart. The wires which feed up the sensor are to a small PCB with what looks like a split arm have detached. But of course there isn’t enough wire to resolder. So seems I am stuck with cadence and no speed, back to training on perceived effort as moving the sensors from other bikes is too much faff. However, this appears to be a mechanical failure and not water induced – none the less I am going to seal my other units just to be certain having found this thread.