When heading out for my daily ride and the Garmin 520 went sleep and refuse to turn on. At first I though it’s out of battery, and plug in the USB charger and nothing happen. Usually it will boot when it connected to the power source but not at this time. 

I spent an hour to Google around for solution, some said required hard reset, some suggest to send back for warranty. Since my unit already out of warranty period, so it will be under my own cost. I have tried few solution including hard reset, but the unit just don’t come alive. 

Until I found one simple solution as below which bring my Garmin 520 back on. If you have the same problem like mine, may give it a try. 

Press the POWER ON button while holding the DOWN button. It might take a few minutes to boot after the splash screen shown.