Garmin Edge 840 keeps on losing sensor connections

[SCD]

I have an interesting and frustrating issue with my 840. Garmin SA seems in no hurry to answer my question or offer any form of support (strange for such a big company?). Maybe somebody came across the same thing - please let me know:

The units keeps on loosing contact to my HRM, power meter and phone. I seems like the Bluetooth and Ant+ radio function crashes. The problem persists even after a normal restart. All the sensors however are working. When this happens I usually continue to record the workout with my Fenix. The watch picks up the power meter and HRM immediately. The only way to fix the 840 momentarily seems to be to reset the 840 in a way that the "Connectivity Software" fully reloads. But it does not do this every time I do the '10s power button' reset. I do not know how to trigger the reload of the "Connectivity software" reliably. I could not make it do it the whole of last week and then suddenly it did do a reload and it was good for 2h and then lost connection again. Unfortunately this is making the unit unusable for my training. Btw, I have the latest firmware installed.

[Furbz]

i had the same issue with a 520 and a 530 unit i had. gave up on garmin and moved to hamemerhead.

no fix for it. i tried everything.

the 130 plus i have now seems ok. same with my fenix - no issues

painful and irritating 

i only moved back to garmin due to the better live tracking and safety - keeps the wife happy.

the hammerhead is a vastly better unit.

[DieselnDust]

  On 3/4/2025 at 8:30 AM, SCD said:

I have an interesting and frustrating issue with my 840. Garmin SA seems in no hurry to answer my question or offer any form of support (strange for such a big company?). Maybe somebody came across the same thing - please let me know:

The units keeps on loosing contact to my HRM, power meter and phone. I seems like the Bluetooth and Ant+ radio function crashes. The problem persists even after a normal restart. All the sensors however are working. When this happens I usually continue to record the workout with my Fenix. The watch picks up the power meter and HRM immediately. The only way to fix the 840 momentarily seems to be to reset the 840 in a way that the "Connectivity Software" fully reloads. But it does not do this every time I do the '10s power button' reset. I do not know how to trigger the reload of the "Connectivity software" reliably. I could not make it do it the whole of last week and then suddenly it did do a reload and it was good for 2h and then lost connection again. Unfortunately this is making the unit unusable for my training. Btw, I have the latest firmware installed.

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My 1030+ does this as well. Kicks out all sensors and it gives me premature low battery warnings.

no fix in sight other than to send it in to garmin for software reload or warranty replacement 

[UnclePolli]

had similar issues, where it connects for a while and then drops again, reconnect.  i did factory reset  disabled Bluetooth and just use the ant+ connection.  also swopped my gamin hr monitor with wahoo and no issues since.

[Andreas_187]

It sounds like the sensors are bouncing between your head unit and your watch? Have you tried it with all other devices well out of range?

[SCD]

  On 3/4/2025 at 9:47 AM, Andreas_187 said:

It sounds like the sensors are bouncing between your head unit and your watch? Have you tried it with all other devices well out of range?

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That is not the issue. The 840 just stops reading all forms of radio - Bluetooth, Ant+ and Wlan. I normally don't even wear my watch while cycling. Only used it to test the sensors, and since they work, I am using the watch as backup.

I reckon it could be caused by an small ICB issue that trips the firmware. Hence it can work again after a full reload; until it trips again. But that is just a theory, I don't have the means to analyze this further.

This could be done by Garmin but they simply don't respond. Is this how Garmin is in SA? I am somewhat bewildered by that.

[SCD]

  On 3/4/2025 at 9:13 AM, DieselnDust said:

My 1030+ does this as well. Kicks out all sensors and it gives me premature low battery warnings.

no fix in sight other than to send it in to garmin for software reload or warranty replacement 

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I was on the fence between the Karoo and the 840. Now here I am with my choice. Damnit.
How is the Karoo in daily live? And most importantly: who is selling and supporting Hammerhead in South Africa?

Edited March 4 by SCD

[DieselnDust]

Hammerhead is supported by cape cycle systems , the SRAM distributor, based in Wetton, Cape Town 

Edited March 4 by DieselnDust

[badiejb]

  On 3/4/2025 at 1:38 PM, SCD said:

I was on the fence between the Karoo and the 840. Now here I am with my choice. Damnit.
How is the Karoo in daily live? And most importantly: who is selling and supporting Hammerhead in South Africa?

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I have both of these units. I am planning on doing a comparison next week between these and the wahoo. Stay tuned. 

[ChrisF]

  On 3/4/2025 at 1:36 PM, SCD said:

That is not the issue. The 840 just stops reading all forms of radio - Bluetooth, Ant+ and Wlan. I normally don't even wear my watch while cycling. Only used it to test the sensors, and since they work, I am using the watch as backup.

I reckon it could be caused by an small ICB issue that trips the firmware. Hence it can work again after a full reload; until it trips again. But that is just a theory, I don't have the means to analyze this further.

This could be done by Garmin but they simply don't respond. Is this how Garmin is in SA? I am somewhat bewildered by that.

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There is ONE way to correspond with Garmin SA.

 

Send you unit in to Garmin, ideally via the shop where you bought it.  (SportsmansWarehouse and CWC have been excellent at this).  Be sure to properly describe the "issue".  As obvious as this sounds, I saw a gent handing in a Garmin unit, and all he kept on saying was "the unit is faulty" ... no amount of questions could get him to say WHY he thinks it is faulty.  Heaven alone knows what he expected from Garmin.  I walked up, showed a print of my heart rate, which apparently spiked over 200 for a long period (while doing a relaxed ride with the 7 year old).  Gave them the event data.  They booked it in, and it was promptly replaced.

 

It takes 2 to 3 weeks to get an answer.

 

1. Under warrantee ... you get a new boxed unit

 

2. Out of warrantee .... Lottery .... possibly a refurbished unit, most likely an amount you pay in on a new unit.

 

Again, this is where SportsmansWarehouse is simply superb ... they get the reply from Garmin, you pick up a unit at your nearest SW .... or like I did, pay in on the next model up.

 

 

 

Sending it in yourself ..... lives tooooo short for this .....

[SCD]

  On 3/4/2025 at 2:38 PM, ChrisF said:

 

There is ONE way to correspond with Garmin SA.

 

Send you unit in to Garmin, ideally via the shop where you bought it.  (SportsmansWarehouse and CWC have been excellent at this).  Be sure to properly describe the "issue".  As obvious as this sounds, I saw a gent handing in a Garmin unit, and all he kept on saying was "the unit is faulty" ... no amount of questions could get him to say WHY he thinks it is faulty.  Heaven alone knows what he expected from Garmin.  I walked up, showed a print of my heart rate, which apparently spiked over 200 for a long period (while doing a relaxed ride with the 7 year old).  Gave them the event data.  They booked it in, and it was promptly replaced.

 

It takes 2 to 3 weeks to get an answer.

 

1. Under warrantee ... you get a new boxed unit

 

2. Out of warrantee .... Lottery .... possibly a refurbished unit, most likely an amount you pay in on a new unit.

 

Again, this is where SportsmansWarehouse is simply superb ... they get the reply from Garmin, you pick up a unit at your nearest SW .... or like I did, pay in on the next model up.

 

 

 

Sending it in yourself ..... lives tooooo short for this .....

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Thanks for the direction. I just came back from Canada. So the 840 is not bought here, and it is out-of-warranty anyway. However I would expect at least the ability to have it repaired. The deal is the same over there. You obviously have to pay something and then get a replacement, just as you describe. Just hope they see the electronics failure in a lenient way.

I will try my luck at Sportsmans Warehouse.

[ChrisF]

  On 3/4/2025 at 2:49 PM, SCD said:

Thanks for the direction. I just came back from Canada. So the 840 is not bought here, and it is out-of-warranty anyway. However I would expect at least the ability to have it repaired. The deal is the same over there. You obviously have to pay something and then get a replacement, just as you describe. Just hope they see the electronics failure in a lenient way.

I will try my luck at Sportsmans Warehouse.

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Worth speaking to them, but I do believe they only handle items bought from them.

 

Sadly you are down to sending it to Garmin yourself ...... and waaaaaaiting those three weeks, then a few more emails.  Couple of Hubbers do have the right email addresses .... @Johnny82

 

And then the lottery of how they want to deal with it.

[Skubarra]

  On 3/4/2025 at 2:49 PM, SCD said:

Thanks for the direction. I just came back from Canada. So the 840 is not bought here, and it is out-of-warranty anyway. However I would expect at least the ability to have it repaired. The deal is the same over there. You obviously have to pay something and then get a replacement, just as you describe. Just hope they see the electronics failure in a lenient way.

I will try my luck at Sportsmans Warehouse.

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Hate to say it but if its out of warranty Garmin SA is not going to be much help to you. Best you can hope for from them is an offer to replace with a refurbished unit at slightly better than normal retail price (but not better than you can get with a bit of digging on the internet)

[DieselnDust]

They will offer you a warranty upgrade cost on a new unit if you are the first owner and it was purchased out of country. That’s what they did with my Edge 1000.

im onto my 8th replacement unit now #semanet

[SCD]

  On 3/4/2025 at 4:25 PM, DieselnDust said:

They will offer you a warranty upgrade cost on a new unit if you are the first owner and it was purchased out of country. That’s what they did with my Edge 1000.

im onto my 8th replacement unit now #semanet

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The 8th replacement unit?

How can this be so bad? I am confused. 

[DieselnDust]

  On 3/4/2025 at 6:20 PM, SCD said:

The 8th replacement unit?

How can this be so bad? I am confused. 

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The software is absolutely crap. Garmin bike computers are absolute garbage. I just keep sending them in and receiving new or refurb units. When I send the current unit back I will receive my 9th unit in 9 years