The Galaxy S3 makes this incredibly easy for all of us, but Samsung doesn’t exactly let us know that we have that capability built in.

I don’t know about you, but sometimes I swear that I see a dead pixel on my phone or that the vibration isn’t working like it should. I want to always be sure that even if I don’t use all the features, they're in good working order.

I usually like to have some sort of diagnostic tool for my smartphones to make sure that every feature I pay for actually works. One great thing I just discovered about the Samsung Galaxy S III (S3) is that it has the diagnostic capabilities built right in.

Accessing the Service menu

The Service menu is activated through a sort of code that you enter into the dial pad of the phone. To get started:

Start your Phone app Get to the Keypad screen Type in: *#0* #

You now should have in front of you a screen with a 5 X 3 grid of options.

Testing the color capabilities of the Galaxy S3

The top row of buttons tests the color capabilities of the phone. Touch each square to see the Red, Green and Blue color tests of the screen. You should be easily able to see if you have any dead pixels on the screen when it is filled with the various colors.

Testing the Receiver and Vibration

Tap the Receiver icon and you should hear a short, high pitched beep. If you don’t, you might have some issues with the Receiver on the phone.

Tap the Vibration icon to test the vibration of the phone. The test should emulate full vibration. This is a reported issue for some users, so it is good to test it out.

Test the dimming and Mega cam

Tap the dimming button and the screen will be divided in three parts; red, green and blue. Tap the screen again and it should dim to about half brightness.

The Mega cam test simply tests out the big camera on the back. Tap it to activate the viewfinder and the rear lens.

Testing the sensors

I didn’t realize that the Galaxy S3 had as many sensors as it did until I tried this one out. Tap the Sensor button and all hell breaks loose on the screen.

The Galaxy S3 will begin running tests for the:

Proximity sensor

Barometer sensor

Lights sensor

Gyroscope sensor

Magnetic Sensor

You can input data, like the sea level pressure to calibrate the barometer and you can even graph the Gyroscope readings by tapping the Graph button. It seems like this is data that would be most useful to a technician, but it is kind of cool to play with.

Testing out the Touch screen

Tap on the Touch icon and the screen shifts to a grid. Tap anywhere on the screen to either color in a box green or leave a dot somewhere on the screen. This test is particularly useful if you think you have areas of the screen that are not responding well to touch. This test should re-assure you that all is working well or it will clearly identify issues that need to be fixed.

Testing the Sleep, Speaker and Sub key

To test if the Sleep function is working, just tap the Sleep key. If Sleep is working on your phone, you will need to unlock the screen and then re-type in the code to access the Service menu.

Tapping the Speaker icon will play a series of tones to test out the speaker on the back of the phone. If you don’t hear anything, make sure your volume is turned up.

The Sub key is what Samsung seems to be calling the Menu and Back soft keys to either side of the Home button. When you tap Sub key on the test panel, you then tap either one or both of the Sub keys to change the color on the screen, which lets you know that both buttons are functioning, as they should.

Testing the Front cam, LED and Low frequency

The last row of icons tests various functions of the phone. Tap the Front cam button to make sure that the front camera is operating as it should. The screen should show you whatever the front camera of the phone is seeing.

Tap the LED button to test the various LED colors. Each time you tap the screen, you should see - in order – Red, Green, Blue, End.

Tap the Low frequency button to test various LCD frequencies.

While some of these tests didn’t really mean that much to me, my guess is that this screen will prove very useful to service technicians who need to respond to customer complaints about features that they experience to be not working on the phone.

Let’s just hope that the local tech at Verizon, Sprint or AT&T know that this exists and use it to cut down on needless repairs or exchanges.