Lot of bugs on F945 since 3.90 ...

The instructions for downgrading (in the link) are quite clear. The problem is to find where we can download the 3.30 files.

To complete my response to Blake ...

I did others functionality tests : the oxymeter doesn't work, the altimeter doesn't work (no altitude is measured, and I can't etalonate it manually !), ... all my watch is dead !!! and this just because an automatic software upgrade.

It's just a shame for Garmin ... I had a Suunto watch for many years, I had NO issue with it, even in case of software upgrading. I had my F945 for 3 weeks,and it's already dead ...

Another analysis if it can help ...

When upgrading to 3.90, I had the issues described below (fast discharge, issue with HR, with compass, ...) but I did a running exercice and the data recorded (except HR) were ok : speed, distance, altitude).

Since, the watch did an update to 4.0, and I did a hard complete reset.

Today, I did again a running exercice. GPS was found, but after several minutes. And during the exercice, only the chronometer works ... speed/distance/altitude/HR remain at zero !

As already said, all the watch is now dead and unusable !!

Just download the files pressing the "Download" button (located at the beginning of the page) ;-) 

lol

On the download button, this is the link for the 3.77 version, which is a beta one.

With 3.90 and 4.00 (which are stable), there is lot of issues, so no way to install a beta software !

What I'm looking for are the files for the 3.30 software ...

If Garmin-Blake could help me ...

The 3.30 downgrade files are included with the 3.77 beta download. I have not tried myself but just follow the instructions given to downgrade to 3.30.

So in your case just copy and rename the downgrade files included with the 3.77 beta to your watch with 3.90 or 4.00 as per the instructions. In theory it should reinstate 3.30 even if you are running the release software.

So ... first of all, thanks for your help. Effectively, the 3.30 files are included in the download.

I did the downgrade to 3.30.

Some issues (which arrived from 3.90 to 4.00) are now ok (the compass is ok, the altimeter is ok, and perhaps some others, I hope the battery consumption).

But some issues are still present : the HR captor is still dead, no measurement, no light, nothing (any idea of the cause ??) ... and I don't succeed to have my SMS notifications on the watch (they were ok before).

So I think that some issues were due to software upgrade, but I fear that some others (the HR captor for example) are due to a watch failure.

What is your feeling ?

I have to wait to contact the ASS because they're closed due to the holidays.

Glad to hear it fixed some of your problems. Did you install the remotesw downgrade files as well? Might be worth doing a hard reset to flush out the watch.