Garmin 645 Music - GPS start up took forever

Try syncing with Garmin express. If you are seeing the 4.40(!), it means you're missing a GPS update. It should be something like 2.50

where did you get this 4.40 version from???

4.40 is actually an old version. They switch to using 2.xx numbering when Galileo was added.

the "!" indicates a mismatch between what the FW is expecting.

Thanks guys for your support. I plugged the watch in Express and installed the latest GPS already. Now it seems work fine.
Just a quick question, normally how long it take to acquire the GPS lock. Me sometimes took more than few minutes. Sometimes worked pretty fast, and sometimes even I let it on for 10 minutes, there are no reaction at all.

where did you get this 4.40 version from???

It was inside the watch, I think it wasn't get updated for a long time. My friend gave it to me few days ago. After upgrading with express, now it turned to 2.50 already.

for me it's about seconds... 5 to 10 - outside between small houses :) sometimes it locks even when i´m at home yet :D

On the watch, if you are getting a slow GPS fix, check in "About" and one of the last screens is for EPO data - you want to see "Current".

Extended Prediction Orbit (EPO) files allow GPS devices to predict where satellites will be in the sky, which reduces GPS acquisition time. With updated EPO files on a device, instead taking 2-3 minutes to find GPS signals, it will usually take 5-10 seconds.

EPO files expire, and are usually only good for a range of 3-14 days. In order to keep the EPO files updated, sync the device regularly.

thanks for this information... really useful!
I had the same issue, and it never occurred to be to try to sync with Garmin Express, as I never use it :)
did the sync, and as soon as i disconnected watch, it informed my I had a GPS update to install,
once that was done, the first GPS took a while (needs to update its sat data i assume) , now its back to it normal speedy fix

cheers

I had the exact same problem as the OP. The exact same screens with the GPS red-bar stuck at "1 o clock". GPS version at 4.40(!). I saw this thread and synced with Garmin express to update the GPS part of the firmware to get 2.50. The EPO files are current.

But GPS lock-in still takes forever, typically around 8K into my run, GPS locks-on, and is on till I finish.

I spoke to support personnel over the phone, and they asked me do a factory reset (which I did). They asked me to delete some files from the filesystem (which I did).

I am still stuck with the same GPS problem.

GPS lock-in still takes forever, typically around 8K into my run

Are you getting a GPS lock before you start running? It will always take a long time to get satellite lock when you are moving. Read Page 2 ofthe user manual - Going for a Run, specifically point 2.