Edge 520 Will Not Power On

Take a look at this thread

Take a look at this thread

I have, and the instructions don't work since I get nothing on the screen at all. The person there has some level of response. I cannot get it to switch to mass storage because nothing happens.

I updated to 7.10 yesterday and had the opposite problem, my 520 wouldn't shut down reliably. It would just reboot when I would hold down the power button and was stuck on the Garmin logo page when I wasn't trying to get it to shut down. After quite a few different attempts, I finally got it to shut down and then it started up like normal. Then later on in the day I decided to check it and it kept on getting stuck on the logo and wouldn't shut down. So I googled how to do a master reset, and that ended up fixing my 520. Sucked though because it wiped all my settings and I had to go through and set everything up again....but at least my 520 is now operating like new again (it's been kinda grumpy for a while now, I think since my most previous update prior to 7.10). Once I got everything back to where I wanted it, I looked up how to back up all my settings in case I had to do the master reset again. No guarantees that this will work for you, but it's worth a try.

Here's the page that I used to perform the reset....but once again...it's going to erase all your settings and restore it back to factory defaults like when you you first turned it on for the first time (although it will have the most recent firmware you installed on it.)

https://forums.garmin.com/archive/index.php/t-348975.html

I updated to 7.10 yesterday and had the opposite problem, my 520 wouldn't shut down reliably. It would just reboot when I would hold down the power button and was stuck on the Garmin logo page when I wasn't trying to get it to shut down. After quite a few different attempts, I finally got it to shut down and then it started up like normal. Then later on in the day I decided to check it and it kept on getting stuck on the logo and wouldn't shut down. So I googled how to do a master reset, and that ended up fixing my 520. Sucked though because it wiped all my settings and I had to go through and set everything up again....but at least my 520 is now operating like new again (it's been kinda grumpy for a while now, I think since my most previous update prior to 7.10). Once I got everything back to where I wanted it, I looked up how to back up all my settings in case I had to do the master reset again. No guarantees that this will work for you, but it's worth a try.

Here's the page that I used to perform the reset....but once again...it's going to erase all your settings and restore it back to factory defaults like when you you first turned it on for the first time (although it will have the most recent firmware you installed on it.)

https://forums.garmin.com/archive/index.php/t-348975.html

I did the reset, as my 520 was pending 7.2 upgrade (Power on + down button) and all seems good now after running update. Will monitor

Hi I had this problem as well. Only just purchased Edge 520, 5 weeks ago so really just getting used to it.
I must have updated to 7.20 at some stage, and left the unit on charge.
Going out for a ride, and tried to switch on the unit with no success.
Back at base I googled the problem and came up with the folowing solution.
Press power on key for 10 seconds. and it worked
Garmin now working fine. This procedure must do some sort of soft reset as none of my settings disappeared.