Fenix 5x plus reboot loop when connected to computer

Hi all, 

I recently picked up a Fenix 5x plus from a reputable eBay watch shop for a bargain price - it had been returned for a broken watch strap, so was being sold as B grade stock, a replacement strap having been fitted (which looks to me to be a genuine Garmin strap).

Received the watch on Saturday and it appears to be in unused condition, as expected. Pairing with my phone was a flaky, annoying experience, but bluetooth can be like that, and once paired the connection to my phone has seemed pretty stable. 

However, I'm having some issues connecting to a computer - any computer (have tried my desktop, another windows laptop, and an old macbook). In MTP mode, the watch enters a reboot loop. The charging screen is displayed momentarily before the watch restarts. Eventually it will just turn off and stay that way. In legacy "garmin" mode, the watch will remain powered on and usable whilst plugged in and charging....until I launch basecamp. When i start basecamp (which shows the watch as connected in the devices list), after some period of time, the watch reboots. It does not seem continuous as with MTP mode. I can't get Garmin Express to find the watch simply for this reason - the reboot is too frequent - and Garmin Express will not find the watch in legacy "garmin" mode.

The vendor on eBay has been really accommodating and has offered to let me return the watch at their expense. However, they tested the watch and found the PC connection to be fine. To me, this feels like a software rather than hardware problem. 

One additional noteworthy observation is that when i received the watch its battery was completely flat so I connected it to my PC to charge it, and when I came back sometime later, the watch had powered on and was on the first-time setup wizard - i.e. asking me to pick a language, weight/height, gender, etc. I went through the wizard as far as setting the clock whilst the watch was plugged in to the computer and powered on without it shutting down or restarting once. Because i couldn't get a decent GPS fix inside, i then unplugged the watch and took it outside, but since the battery had hit about 65%, i just left it on my wrist the rest of the day - i didn't go back and reconnect it to the PC. Then, later in the day, the watch picked up an update via Garmin connect - it had been running version 12 when i received it, and updated itself to version 14.0.

On Sunday, i plugged the watch into the PC to mess about on Garmin Express and that's when the reboot loop problem seemed to start. 

So, to me, it looks like it potentially started when the software updated to 14, and is related to an attempt to establish a data connection to the watch - occurs on connection in MTP mode as windows tries to index the drive as external storage, or when basecamp is launched in legacy mode when presumably basecamp tries to talk to the watch. I'd like to try and repeat the version 12 experiment but of course i can't because the firmware downgrade process requires a computer connection to transfer the old files. 

I'm currently debating whether i can live with this as a fault, given the device otherwise seems rock solid. Almost all interaction with the watch is via the Android app, including syncing routes etc. The only issue is that i think i need a computer connection to upload additional third party maps (unless someone can advise me different). 

I guess my questions are: 

1) has anyone had this problem and found a way to fix it? Is there anything i can do with developer mode on the watch?

2) does anyone know a way to either downgrade the watch firmware to 12 or perhaps try an update to the 15 beta without a PC connection? 

3) my watch shows v14.0 in the about screen, but i am aware there have been multiple minor releases of 14 - 14.71/72/73. If the about screen is to be believed, i'm not sure why my watch isn't updating to those versions. Is there a way i can do this, again, without a PC connection?

Apologies for the long and rambling message, and thanks for any help that can be provided

  • The same thing happened to me a few times, but I always fixed it: apparently this happens when the watch has something "corrupted" that is trying to sync with the computer. If you had stuff on your watch, I would suggest deleting it (activity .fit files with the watch connected to the computer without launching Garmin Express, using Windows Explorer), but the watch is new so probably your best bet is doing a full reset. You can also try disinstalling Garmin Express on your computer and re-installing it.

  • That certainly sounds plausible. You're right that there is very little on the watch - some custom watch faces and a few widgets, but i tried the PC connection prior to installing these with the same effect (it was before phone pairing also). I should have mentioned, but I've also tried doing a full factory reset, then connecting the watch in a completely vanilla state, and the behaviour is the same. But it's worth saying also that the "factory reset" seems just to clear the data. It does not appear reflash the device from some recovery partition which contains the original factory ROM. So, after the factory reset, I'm still on version 14 rather than 12 that it seems to have shipped with. 

    I also should have mentioned that this seems to happen irrespective of whether garmin express is running - I'm pretty certain it isn't even installed on the macbook. In other words, i can't achieve a stable MTP connection at all, so I can't even browse the file system of the watch using explorer. I have also tried removing any and all garmin software and drivers from my machine and installing the latest garmin express, which also didn't work. This all means i can't down- or up-grade the firmware. The only way i can update the watch is via garmin connect on android.

    I might try and repeat what happened when i first plugged the watch in, see whether that now fails (i.e. booting up the watch after a factory reset whilst plugged in). Would give more confidence that it is 14 that's the problem if it fails. If the watch does not enter a boot loop when i do that (and one assumes does not appear as a device in windows as a result), i guess the only evidence i have that it ever worked on version 12 is the claim from the vendor that they tested it. 

  • Update: after another factory reset, i can connect the device without reboot cycling issues whilst the startup wizard is displayed - i.e. i'm on the language select screen and the watch is connected. In USBDeview the device now shows up as a "Garmin USB GPS" with a driver version of 2.3.1.0. However, i cannot see anything to browse in windows explorer. As soon as i progress through the wizard and complete the initial setup, it displays the charging screen for a few moments before restarting again, as per usual. 

    So i think that means my initial experience having the device connected before completing setup doesn't mean anything - certainly doesn't prove 12 was ok and 14 isn't. Perhaps it is just faulty after all!

  • Hello. I have the same problem for all with fenix 5x plus connected with macbook.

    Once when the watch sometimes not restarted, if i changed Settings - System - USB Mode MTP (Media Transfer) to Garmin, then if you're lucky, the clock gives you a choice when you connect to USB to Mac  - yes or no - and Garmin BaseCamp and Garmin Express sees the watch if you have not chosen anything! But if you choice Yes - restart.. No - if lucky watch still work if no lucky - restart or off.

    Another way yesterday i will try full reboot with turn method turn Start + back-lap + light etc, so I immediately connected the watch via a USB cable, after rebooting, and entered the time data, weights, etc. when they were connected., then even Garmin Express immediately determined the watch, I finished connecting to Wifi, and then I was even able to update the maps.


    But when I went to sleep, in the morning the clock was turned off, after a long hold of Light, I turned it on, and of course, while connecting to the Mac, they rebooted again. And they give it until - until I disconnect the usb cable.

    I did not try to connect in PC with Windows 10 - but i think problem is the different problem.