Here is how to access it and the most useful tests you can run.
If you are on US Cellular and having reception issues, you might want to check the actual signal numbers rather than the "bars." galaxy s5 us cellular diagnostics tool
View real-time data from the accelerometer, proximity sensor, barometer, gyroscope, and magnetic sensor. Here is how to access it and the
: Verifies the front and rear cameras can initialize and focus. 2. Advanced System & Battery Diagnostics galaxy s5 us cellular diagnostics tool
Here’s a detailed write-up on the .