Back button not working and other funkiness

That's odd - don't recall similar reports.

Am also puzzled how you managed to get that reset screen as that requires the lap (aka back, lower right) button to be pressed while powering on the device. It sounds as if your button is somehow "pressed in".

Does that button appear to be physically pressed in? If you press it does it go in a bit and then pop out again (as mine does)?
Maybe there is a mechanical problem there.

Another reset to try is a "hard reset" where you press in the power (top left) button for at least 15 secs until it powers off.

The other one is the full master reset where you do steps below. Would try a hard reset first however.

Hold the light button until the device prompts "Shut Down?".
Select "Yes"
Hold the two right buttons, <Start/Stop> and <Back>, while turning the device on by pressing and releasing the light button.
Wait for an audible beep and release the <Start/Stop> button.
Wait for a second audible beep and release the <Back> button.
The non-vol clear was successful if the device finishes powering up and goes Setup Wizard page.

Prompted Non-Vol Clear - Clears NV and deletes all default FIT files (Settings.fit, Sports.fit, Totals.fit, Records.fit and Schedules.fit) and any files in the NewFiles folder. This will not delete Activities, Courses, or Workouts etc.

Press and hold the LAP button while powering on the device
Accept prompt

Thanks Tim. I'll try to address your questions.

1. When I power it back on, it asks me, "Clear user data?" and it gives me choices of "Yes" and "No". When I select "No" and click the upper right button, it attempts to move forward with the command but it is not successful. When I use the back button (lower right), it does nothing.

Then, after a few minutes, it finally moves forward, (as it did just now when I did it again), and the watch beeps at me in rapid fire, as if it's catching up on the times that the back button and other buttons have been pressed. Then it beeps randomly.

2. The back button does not appear to be "pressed in." But I am new with this watch, so it's possible that it is pressed in a little and I am not able to tell. I will say that it doesn't have the same responsiveness as the button on the upper right.

3. I am trying the hard reset right now. I'll do this before trying the master reset.

Thanks again for your help!

Regarding the hard reset, it did not make any difference or improvements. All the same behavior as described already.

I tried the full master reset, and it does not complete the reset. It's stuck on the Garmin logo.

TIMGROSE -- any suggestions of what to do now? I am thinking the watch is broken and needs to be returned and replaced.

Needless to say I am very bummed. I have an open water race next weekend :-(

Unfortunately I would now have to think that your watch is "broken" and you are best advised to seek a replacement.

Where did you buy it from? If it was a physical shop perhaps you can go through them otherwise Garmin support. Had not realised they only provided a Mon-Fri "office hours" service both in USA and UK and elsewhere so it seems.

Sorry to bring back such an old threat, but yeah me too :(

Yesterday the lap button began activating itself while swimming and then it got worse while running. It sometimes worked fine while other timeds just created several laps per second. I clearly saw liquid coming out of the lap button, which I think is related to the false lap trigger. At least it was working when pressed, but today it just doesn't work at all.

For the record I run 3 times a week, swim 5 times, and use it constantly 24/7 as a tracking device.

I'm sending it back for a replacement. Still I'm assuming I will need to do this periodically until the guarantee expires.

I'm sick of Garmin quality control (o just plain bad ingeneering). Three 910xt and one 920xt had the barometer broken. Hence I decided to try the 735xt, but it's broken in less than 3 months. I feel hopeless.