Garmin is one of the most well-known and successful manufacturers and distributors of global-positioning systems in the world. GPS devices are frequently used in automobiles and other vehicles to navigate the driver to a destination without the concern of getting lost. Garmin GPS devices are intended to be as easy to use as possible, but they can sometimes experience problems. If your Garmin GPS won't turn on, there are several options for fixing it.
Check the screen lock. If the lock switch is in place, the device won't function until it is switched off. It is normally located on the top of the device frame either near or connected to the power switch.
Plug your Garmin into a wall outlet with your power adaptor. Its internal battery may be drained and your car charger may be malfunctioning. The wall outlet should charge the Garmin adequately and allow it to resume normal operation if the power supply is the problem.
Connect your Garmin to your computer via a USB cable. Some Garmins have defective firmware that hinders their operation, and downloading updated programming from Garmin will fix the problem. This is especially possible if your Garmin is a part of the 7X5 series, 800 series, 8x5 series, Zumo 660 and both the 620 and 640 models of GPSMAP. The GPS may respond to the computer connection and allow you to access it through the computer.
Attempt a reset of your Garmin by pressing down on one of the four corners of the touchscreen while pressing the power switch. This should prompt the device to start up in "Maintenance Mode," which will allow you to download firmware and reset to factory settings if needed. Which touchscreen corner to press on to activate Maintenance Mode varies per model.
Contact Garmin at 1-800-800-1020 to discuss repair if the device still won't turn on, since you may have a faulty GPS or a bad battery.