Problems: New Edge 830 Version 8.00 Now Available

Are you using Garmin maps or have you loaded some others?

Late to respond (no clue if this is still an issue for you or not but it may help others who are boot looping uncontrollably)-

I was able to get back to 6.2, the most recent version that unlocks trailforks for me and is stable (7.1 is stable as well if you don't suffer the trailforks issue) by forcing it into mass media mode (press and hold lap button while its plugged in until it shows up on your pc), load the preferred release  GUPDATE.GCD file in the "Garmin" folder, disconnect and then press and hold on the screen in the top left and right corners till it loads. You'll have a brief moment to tap "yes" to the loading the older OS (bottom right) before it loops again.

You may have to do this several times before it works. When you get it stable again, don't let it auto update via Express.  Your profiles, sensors and phone setup will all be gone and need to be setup again. 

forums.garmin.com/.../new-edge-830-version-7-10-now-available

not u/676771 but here's another pile of data points-

I'm pretty confident its not so much a hardware issue but more of a software one as it didn't start until I updated past 7.1 (to the 7.23 beta OS) on my original, bought close to release unit (sensor bundle unit). Up to that point, it had been rock solid with regular and beta OS releases with no issues updating CIQ apps or trailforks map sets.

My first replacement device- on OS 7.1 had the "cannot unlock trailforks" issue and could not switch profiles without rebooting.  On OS 8.0 it got even more unstable- I could not switch profiles without a reboot and had problems with phone and wifi connections constantly having to be reset.

My 2nd replacement device- shipped with OS 6.2, is stable and can unlock trailforks. But it's stuck with the 2019.10 trailforks map set despite the unlock (deleted and reinstalled on the phone and via express with no success). On 7.1, trailforks cannot be unlocked but can sign in and get to my routes and see the trails, it is otherwise stable. On 8.0 and 8.1, its wildly unstable with perpetual boot loop issues (8.1 crashes mid-load, its that bad).

That said, there may very well be a hardware issue buried in here as well given how my first replacement behaved on OS 7.1. Compared to the original which was completely stable and 2nd replacement with just the persistent trailforks issue. And that not everyone is having the boot loop issues when they update. 

As far as maps- the original unit used a collection of 24k Garmin maps in conjunction the stock and trailfork IQ map sets. The first replacement only had the stock maps installed and 2nd replacement is still getting setup andhasn't received my 24k maps yet.

I use OSM, but on 8.00 it doesn't work even if i leave only garmin maps on device (also deleted 3-party map files, not only switched off)

Mine is still in 6.20 so far the Edge is stable and performing well.

After upgrading to 8.0, my Edge 530 also went into an boot loop. After resetting to factory settings, it started up, but also reboots when I using third-party navigation maps. On 6.2 and 7.2, there are no problems when using third-party navigation maps, but now if I go into history and view the route of any of the workouts there, and then go to the navigation menu, and I open the map view, the device reboots regardless of which software version I use.

Also, in the diagnostics menu (to get into it, you need to turn off the device, press the power button, and then press and hold the workout start button) the device does not pass the memory test.
Gives the following message: RAM Test: Pass, ROM Test: Pass, Basemap Checksum Test: Fail
I think the problem is hardware, just before the update to version 8.0 it was not so pronounced and many who encountered this problem now, may not have noticed it earlier.