Acer B1-720 Service Manual page 30

2. Double Touch Test
The Double Touch Test is used to test 2 points touch on the panel.
Use two (2) fingers to draw from the left to the right along the blue bars.
When the top bars has been drawn successfully, continue to draw on the blue bars on the right,
then on the bottom and on the left.
Each side must be drawn three (3) times. If drawing fails for more than three (3) times, the Double
Touch Test will fail.
3. RGB Test
Press Vol + hardware key to start the test. Press Vol - hardware key to switch to the next
colored screen.
The screen sequence are as follows: Red-Green-Blue-Black-White.
Judge the test result by tapping the "Pass" or "Failure" button. Or, press the "Retest" button to
do the retest.
2-5
Figure 2-5. Double Touch Test
Figure 2-6. RGB Test
Diagnostic Utilities