The Garmin Forerunner 305 GPS trainer is a tool that monitors your heart rate to improve your fitness regime. The unit straps to your wrist like a watch or wraps around your chest to measure your heart beat. That information then displays via a digital readout on the face of the device. The website REI reports the Forerunner 305 calculates calorie burn, records lap history up to 200 workouts and provides a pace alarm to control speed. If your heart monitor is acting erratically or refuses to turn on, some troubleshooting may pinpoint the problem.
Check the battery if the unit does not turn on. The Forerunner comes with a rechargeable battery. Place the unit on the charger with the display facing upward or connect it to your computer via the USB cable provided.
Acquire the satellite signal if the unit does not register your GPS location. Step outdoors and find an open area free of tall buildings or trees. Press the power button on the left side of the device. Ensure the small slot located just under the display faces upward and is not blocked. The Forerunner automatically searches for a satellite signal.
Rescan for sensors if the unit does not display data correctly. Turn the unit on and select “Settings” from the main menu by pressing the mode button on the left side. Choose “General” and “Accessories” from the settings menu. Press the arrow keys on the right side of the device to highlight “Restart Scan.” Click the “Mode” button on the left to start the scan.
Remove the display device from the strap and wipe off the sensors on the back with a clean cloth. Dirt and debris can affect the workings of the sensors.
Tighten the strap to reposition the device against your body. If the sensors do not make consistent contact, they may read inaccurately.
Wear a cotton shirt if strapping the unit around your chest. Synthetic fabric may affect readings.