Dropouts on Garmin Edge 520

[Kessler]

Devices: Garmin Edge 520 w/ all firmware updates, PowerPod ANT+ w/ all firmware updates.

Symptoms: Turn on PowerPod, spin up the speed and cadence sensors, Edge 520 detects all three (plus ANT+ HRM and phone's Bluetooth). Start riding, everything looks good. Next time I check the Edge 520 display, power is reading 0W (despite non-zero cadence, and about 100W effort). For the remainder of the ride, reading on the Garmin will randomly alternate between a valid power reading, 0W, and __W. The valid readings usually don't persist for more than a few seconds. At no point does the Garmin ever report that it's lost connection, or reconnected the PowerPod. Here's a snapshot from the Garmin data:

bad_power_graph.png (60.24 KiB) Viewed 2570 times

This is about the fourth time this has happened in the six months or so that I've had the PowerPod. The vast majority of the time it works fine, but just when I think I'm out of the woods, the problem pops back up. The data in the PowerPod is fine and doesn't show any dropouts. I can merge the Garmin data with the iBike file post-ride, but that doesn't help me much during the ride.

I suspect the first reaction will be that it's Garmin's problem as their track record for software reliability is less than stellar. But the 520 is a mature model and I've used this particular unit with two other DFPMs, a Smart Trainer, three different HRMs, and a couple of different speed/cadence sensors. The only device I've ever seen this problem with is the PowerPod. And if there was some special susceptibility in Garmin's software that only affects the PowerPod, one would not expect it to work perfectly the vast majority of the time.

I really want to like the PowerPod. It performs well but it's much more "fiddly" than any of the DFPMs I've used. I could live with that if it was totally reliable, but for me it's not. I'm open to suggestions, but since the problem seems to crop up only at inopportune times, I'm struggling with the question of whether I'm willing to risk it messing up a really important ride.

[Velocomp]

Please post .ibr ride file from Isaac.

[Kessler]

Please post .ibr ride file from Isaac.

Sorry for the delay, it's been a busy week. The .ibr file is attached. Disregard the time/date in the file -- the PowerPod had apparently lost track of time due to a low battery. I charged it but didn't connect to Issac prior to the ride so it recorded with a bad time/date.

[Velocomp]

Your ride file data is 100% intact. Speed and cadence sensor data are normal, too, so there is no problem with your ANT sensors.

I have used a 520 for the past 3 years and have had zero issues. We have many other customers who also use the 520; again, without complaint.

I am assuming your 520 is mounted very close to your PP--within a few inches. If so, there is no problem with weak signals between the two devices.

It sounds like you may have quite a few sensors paired to your 520. I suggest the following:

1) Do a hard reset of PP, then ride. This MIGHT fix the problem (assuming PP is the problem)

2) You can also try removing DFPM sensors from your 520 profile. It's possible that your Garmin is searching for sensors during the ride; why this might happen I do not know

If these steps don't work let me know.

[Kessler]

Your ride file data is 100% intact. Speed and cadence sensor data are normal, too, so there is no problem with your ANT sensors.

I have used a 520 for the past 3 years and have had zero issues. We have many other customers who also use the 520; again, without complaint.

Thanks for checking. I do have many rides where everything worked fine. It's the infrequent but recurring nature of the problem that makes it so frustrating as it typically surfaces well after I've started to trust things again and it's incredibly difficult to know with any certainty if changing something has any effect.

I am assuming your 520 is mounted very close to your PP--within a few inches. If so, there is no problem with weak signals between the two devices.

Correct. It's on a Barfly Garmin/GoPro mount directly under the 520.

It sounds like you may have quite a few sensors paired to your 520. I suggest the following:

1) Do a hard reset of PP, then ride. This MIGHT fix the problem (assuming PP is the problem)

2) You can also try removing DFPM sensors from your 520 profile. It's possible that your Garmin is searching for sensors during the ride; why this might happen I do not know

I can certainly give that a try. Is the hard reset done through Issac or is there a magic button sequence for it? I have one DFPM that I need to keep paired with the 520 (as I ride that bike often) but I can clear out some of the other sensor parings. Unfortunately, it could take months to see if the problem resurfaces. Thanks for the suggestions.

[Velocomp]

1) To hard reset PP, press-hold its button for about 12 seconds. You'll see the light go out momentarily, then start flashing again. Release the button. You should connect PP to Isaac afterwards, to reestablish its date/time clock.

2) I am 99.9% convinced that its your Garmin misbehaving. This is because PP is working properly (ride files are fine) and your PP is very close to the 520. Hopefully removing sensor IDs from the Garmin will do the trick.