Troubleshooting Mobile Devices Lesson 004: Mobile Display Issues

What does mobile display issues encompass?

Broken screens, dim images, digitizer issues, calibration issues, and stylus not working.

What is important to make sure of when assessing screen damage?

That the damage is limited to just the screen.

What are the parts of a mobile device screen?

Glass, digitizer, display, and backlight.

What is a good indicator that only the outer glass on a mobile device display has been damaged?

If the screen still shows images and is responsive.

What does dim images usually indicate?

A backlight problem.

What do older mobile devices use to backlight a display?

CCFLs.

What does CCFL stand for?

Cold cathode fluorescent lamps.

What do CCFLs require for power?

An inverter.

What needs to be troubleshooted when it comes to dim screens in mobile devices?

Figure out if the issue is caused by a power supply issue or with the component itself.

Digitizer

Layer of a touchscreen that detects the user’s input.

What happens when a digitizer fails?

The screen is not responsive to touch.

How can a digitizer get damaged?

From failing, force, or liquid damage.

What is something that a tech needs to check for on the screen when the digitizer isn’t working?

That a screen protector isn’t interfering with it and dust or debris between the screen and the digitizer isn’t interfering with it.

What is something a tech can try to do to fix issues concerning the digitizer before doing anything physical with the device?

Restart the device.

If restarting doesn’t work, what should a tech do next to fix a digitizer issue?

Check the connections inside of the device, especially if the screen has recently been replaced.

What is a common reason for a digitizer to not function?

A disconnected <term> cable, preventing input from reaching the motherboard.

Calibration Issues

Occur when touch inputs register in the wrong locations.

How does a tech recalibrate touch input on a touchscreen?

Through a software that helps to re-align it.

how does cursor drift occur in laptops that use touchpads?

High sensitivity settings and accidental contact when typing.

What are the things a tech can check when troubleshooting stylus issues?

If it is charged or powered on, if it’s properly paired, if the screen is damaged, check for software updates, and check the tip.