How to: Turn the Pro 550 + Back-light on
You can activate the Garmin Pro 550 + Back-lite by simple short pressing the power button located on the right side of the handheld near the top. (near the base of the antenna). You can also turn the Back-light off by simply short pressing the power button again.
Note: if you hold down the power button instead of a short press-and-release you could turn your Pro 550 + handheld off.