Related
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

GPS issues/drop-outs

zmarkella
over 8 years ago
So, I've been using the 935 since the day after it was available in the UK without any issues. That is, until last Sunday.

Headed out for my long run, things going well, when I noticed that the 1k autolap times were a bit off. The first few kms were a steady 5:30(ish), when the watch started to report 6:00, then 6:30 followed by a 4:10. Now this was odd as I did not change my pace at all. Stopped the activity (selected resume later), then back to watch face. Start run, continue activity, wait for GPS and off I go again.
Then my wife sends me a message, saying that according to my livetrack session, I'm not moving. So, I thought that the stop/start broke the livetrack. Stopped and saved the run, restarted the watch (as I could not end the livetrack session), started a new run, then everything seemed OK. (After checking the livetrack at home, it was still showing me in our front garden...)

After downloading the data, it was far from OK. There are massive gaps in the GPS track and I have no idea why. I've tracked over 500km with the watch and had no issues until last Sunday.
I went for a run today, same GPS issues.

Last 'working' run:
https://connect.garmin.com/modern/activity/1690665078
(external HR, livetrack)

Sunday run, part 1:
https://connect.garmin.com/modern/activity/1694156439
(external HR, livetrack)

Sunday run, part 2:
https://connect.garmin.com/modern/activity/1694183388
(external HR, livetrack)

Today's run:
https://connect.garmin.com/modern/activity/1697624270
(external HR)

I have the compass added as a data screen. The compass becomes very sluggish to update during a run and sometimes it doesn't even show the heading. It stays blank.

Anybody noticed similar issues?
Things to try? Master reset?

Cheers,
Zoltan
  • 0 over 8 years ago
    weird, master reset then ring Garmin UK Support would be two suggestions!
  • 0 over 8 years ago
    I posted in another thread about this, but I have noticed this watch is a lot less tolerant at being worn "loose" than my 235. I will lose heart rate when walking around if it's not sufficiently tight on the wrist.

    I've worked out with my 935 several times and have no "gaps" in heart rate, but I am already in the habit of tightening my watch up before working out. I only lose heart rate if the watch isn't tightened enough. What else will happen is if I'm typing on a keyboard, I'll rest my wrist down, and the watch will pop up just enough to lose heart rate.. again indicating it isn't quite tight enough.

    I'm guessing this is now a problem but not with my 235 due to the less pronounced OHR "hump" on the back of the watch, so it requires a tighter seal to function.

    Hopefully that's the issue here, and you didn't get a dud!
  • 0 over 8 years ago
    @rtperna: got no issues with optical HR - tried twice and didn't like it. Prefer the HR strap as the data is more reliable + the battery drain is lower on the 935.

    Recorded my bike ride to home (without changing anything) and GPS was spot on.
    https://connect.garmin.com/modern/activity/1697971504

    Wondering it it's got something to do with the external HR...
  • 0 over 8 years ago
    Are you sure you had a green GPS status on today's run as it looked to struggle soon after starting?
  • 0 over 8 years ago
    Are you sure you had a green GPS status on today's run as it looked to struggle soon after starting?


    Yup, got the 'GPS is ready' message before starting.

    Looking at the raw data, I had correct GPS data for the first 1 min 5 secs. Then nothing until 4:14, where I got GPS data for 9 seconds, then a gap until 4:40. This 'some data/lots of missing data' repeats until the end of the file.
  • 0 over 8 years ago
    Bit strange then. I can't recall any GPS drop outs myself as yet. External HRM can't see being a factor as I nearly always use one and there has never been any correlation between the two I can recall with any device in the past.

    On previous devices I used to get into a routine of waiting a bit after seeing GPS is ready before starting and also looking at a data page showing speed or pace and making sure this had zeroed out before starting.
  • 0 over 8 years ago
    Yup, strange indeed. Especially, since I ran over 500k with it using the same setup (external HR, livetrack) and saw no issues.
    Oh well, I'll try again today as I'm going for a run shortly - if it's still acting up, I'll give it a reset.

    BTW, is the master reset now called 'Clearing User Data'? Or is there a different key-combo for the master reset.
  • 0 over 8 years ago
    Yup, strange indeed. Especially, since I ran over 500k with it using the same setup (external HR, livetrack) and saw no issues.
    Oh well, I'll try again today as I'm going for a run shortly - if it's still acting up, I'll give it a reset.

    BTW, is the master reset now called 'Clearing User Data'? Or is there a different key-combo for the master reset.


    On the 935 I'm not sure, but on my 235 there were two resets; clearing master data, which does just that, and a return to factory settings function which involved holding down "up" and the "light" button for 10 seconds or so. That does a deeper reset than simply clearly the master data, and some people had to do that from time to time when their OHR got jacked up and stopped working. Never saw it myself, thankfully, though I had to do that once when my 235 stopped tracking steps.
  • 0 over 8 years ago
    Both effectively do the same thing but the one where you have to press buttons is more for times when you can't get to the menus and so is largely a "last resort".
  • 0 over 8 years ago
    This might be of assistance if you have GPS issues. I put together a Connect IQ app (a data field in this case) which displays the reported GPS signal quality and also writes it to the FIT file so you can see it in a graph in Garmin Connect afterwards. GPS signal quality is reported as a number from 0 to 4. 3 and 4 are usable, 2 or less is a problem. The data is fairly crude, but unfortunately it is the best Garmin gives us.


    https://apps.garmin.com/en-US/apps/e3f85a7a-7241-4fd1-b6b3-39eddf26ed43