If you use an unlicensed screen protector on your Touch Screen please be aware that this can reduce the sensitivity of the Touch Screen. In this case please remove the protective film and retest the device after re-calibrating the Nintendo DS Lite.
Inspect the surface of the touch panel for any marks, scratches or wear and tear. This may impede the operation of the touch panel. Should the touch screen be scratched this fault can only arise from an external event, e.g. this may occur when treating hardware, accessories or games improperly. In this case, the warranty becomes void and repair charges will apply.
Attempt to recalibrate the Touch Screen.
Note: Calibration must be done with a stylus.
a. Remove all games from the Nintendo DS Lite.
b Turn the system on by pressing the Power Button.
c. Press the A Button when the "Touch the Touch Screen to continue" message appears.
d. When the main menu appears, use the + Control Pad to place the cursor over the Settings Menu Panel (icon displayed right) at the bottom of the lower touch screen, and press the A Button.
e. Use the + Control Pad to place the cursor over the orange icon that looks like crosshairs (the right-most icon), and press the A Button.
f. Please make sure you tap the displayed calibration points precisely (upper left corner, lower right corner, middle). If you have done this correctly a message 'Calibration complete' will show up.
g. When complete, four squares will appear, allowing users to test the Touch Screen sensitivity. Should any of these fail to change to blue in colour when touched or alternatively should the unit not allow you to complete calibration, the DS Lite will been to be returned to Nintendo Australia for inspection.
Foreign material caught between the Touch Screen and the housing of the Nintendo DS Lite may cause it to respond incorrectly. Try the steps below to remove the foreign material:
Use a brand-new, soft to medium-bristled toothbrush which must not be wet or exposed to any liquid.
Do not use any liquid or cleaning solution, as this may damage the system.
The Touch Screen cleaning process should only be performed when foreign material is visible.
5. Hold the Nintendo DS Lite so that the edge of the screen that you need to clean is at the top.
6. Use your thumb to gently press down on the screen near the edge that you wish to clean to make a slight gap between the screen and the housing. This will make it easier to brush out the particles.
7. Press the bristles at the top of the toothbrush under the gap that you have made. The plastic part of the toothbrush should not touch the screen at all, since the hard plastic may damage the screen.
8. Gently move the bristles from side to side to brush out the particles. When you are finished, check to see that the particles have been removed.
9. Repeat steps 2-4 for any other edges that have visible contamination. (You may need to recalibrate the Touch Screen after cleaning.)
Should none of the above correct your issue, the Nintendo DS will need to be returned to Nintendo Australia for inspection/repair.