21.18 lots of sensor disconnects and reconnects - Edge 840

I installed 21.18 on my Edge 840 last night and went for a ride.  My power meter was connected, but didn't show any data for the first 5min.  Then it would drop and reconnect, then my HRM Pro would do the same.  Lots of disconnected and reconnects last night when this has been rock solid before.  Feels like I'm on my old 530 again.

  • I encountered a similar phenomenon at 21.17.
    At that time, I discharged the HRM and reset it, and it was able to read the sensors. For some reason, the power meter was also able to read.

  • Had a sensor disconnect the other day, which froze my unit and rendered the varia radar inoperable.

    I didn't realize that it froze, and it put me in quite a dangerous situation, being temporarily unaware that cars were behind me without being notified of them.

    I hate to be a conspiracy theorist, but with the launch of the 1050, it seems suspicious that our 840 is suddenly plagued with problems it never had.

    Over the last few updates my 840 has been terrible with navigation prompts, disconnects, unreliable GPS, and now hard freezes.

  • I’ve been having a similar problem. Start up my 840 and all the sensors(HR, speed, power) all show up as connected, then I start my ride. 3 times now and within 5 minutes of starting my ride all of the sensors have dropped out and the only way to get them back working is to delete them from the unit and reconnect them. Which as you can imagine is a pain in the ass when you’re beginning a ride. 

  • I used to have this problem with my 840 when I let it sleep between rides. When I do the full shutdown (long press power button and press the red shutdown option) the sensors stay connected on the next ride. Its not very convenient but better then losing your sensors mid-ride.

  • Thanks for that! Thats pretty much what I’ve been doing. Quick press of the on/off to put it to sleep after the ride has synced to Connect and Strava. My last ride, with the new public beta (23.0 something firmware) had no issues, but I’ll give the full shutdown a try. Doing a full shutdown is not even remotely as inconvenient as having to uninstall and reinstall the sensors when I’m on a ride. Again, thanks for the tip. 

  • I do that too for this very reason.  Still seemed to have problems recently though.

  • Hmm. Haven't had any issues here but im wondering what kind of sensors you use. 

    I've been using Varia radar, Coospo HR9 hr monitor, and Favero Assioma power meter plus a manual speed sensor on front wheel. No issues disconnecting.

  • I’m still having this issue with 24.19

    Exactly as above: sensors will connect then disconnect if i use sleep between rides. But no issue with full power shutdown.  

  • I have the same problem. Garmin 840 (fw.24.19) with Varia RTL515 (fw 3.34). Unpredictable behaviour.

    Scenario 1: Wake up (or power on) Garmin 840, Power ON Varia (radar with backlight). Connect radar+Lights as expected. Then after few minutes riding disconnect radar and light and cannot connect again.

    • Solution is Remove radar+light sensor Power OFF Garmin, Power OFF Varia and reconnect agan. ... TERRIBLE!!!

    Scenario 2: Everything is working. 2/3hours riding, then go to the shop Power off Varia. Then Power ON varia, but connect only Radar and not backlight (light is working but cannot see battery state and cannot change flash/solif/off/peloton state).

    • Solution is remove Light sensor and Add new with sensor 6-digit code. (cannot find the light automaticaly). Also TERRIBLE!!!

    This is extreamly anoying when I ride with friends. They must waiting for me and Im "The idiot with Garmin". Some of the friends uses radar/lights Magene L508 which is almost half a price and it works as expected.

    Garmin please solve this problem.

    It is CORE functionality of the Varia backlight.

    Thank you

  • Hello all, I apologize for the delayed response, and thank you for your participation in the Garmin forums.

    We are investigating reports of sensors not reconnecting after resuming  from sleep on Edge x40 devices. It sounds as if several users in this thread are describing this behavior.

    If you have experienced similar behavior, do I have your consent to reach out to you externally and collect more details?