Narrator: In this lesson,
we're going to talk about mobile display issues,
and these come down to four main areas,
broken screens, dim images, digitizer issues,
and calibration issues.
First, let's take a look at broken screens.
Now, mobile devices are very easy to drop and damage
because we take them with us everywhere.
Now, modern mobile devices do use Gorilla Glass
and things like that,
which are a very strong form of display.
But even with this superior glass technology,
if you drop the device from one meter,
which is around three feet or higher,
it will end up cracking the display.
If you crack the display, we call this a broken screen.
Now remember, when you're dealing with a mobile device
that has a touchscreen,
there are multiple different layers
inside of that screen, including the glass, the digitizer,
the screen itself, and the backlight.
So any of these components could be broken when you drop it.
But if you have a touchscreen display,
and you're still able to operate that touchscreen
and see things through it,
this might mean that just the glass itself is broken.
Again, it's something to consider
as you're doing your troubleshooting.
Is it the glass is broken?
Is it the digitizer, the screen, or the backlight behind it?
And this brings us to our second mobile device issue,
which is dim issues.
If you have a screen
and you can very faintly make out the image,
but it is really dim,
this usually indicates that you have a backlight issue.
Now, most modern displays are going to use LED backlights
to be able to brighten up that display.
And if those backlights fail,
you're going to have a very dim display
and you won't be able to read it very well.
Now, on the other hand, if you're using an older laptop,
you might still be using an old CCFL,
or fluorescent light backlight.
In these cases, there is two components
that you have to worry about.
One is the backlight itself,
and one is the inverter
that provides power to that backlight.
In either of those cases,
you're going to have the same symptom though,
which is a dim display, because if the inverter has failed,
it's not going to be able to power the backlight,
and if the backlight has failed,
it's not going to be able to provide the light to the screen
in order to make that image bright.
Now, the third issue you might have with mobile displays
is digitizer issues.
As I said, there are four parts to most displays.
You have the glass on the front,
the digitizer underneath it, the screen,
and then the backlight.
When you're dealing with a digitizer,
this is the device that is underneath the glass
that responds to the input that a user is doing.
So, if you're touching the screen on a touchscreen
and nothing is happening,
usually this would be a digitizer issue.
This is especially true
when you can see everything on the screen.
There's no cracks in the glass,
and everything is fully bright,
but when you touch things, nothing is happening.
Normally, you'll find that digitizers fail
because of shock damage from dropping things,
or liquid damage.
If you can rule out these two things,
then it may be the digitizer itself that has failed,
and in these cases you want to verify whether or not
there's a screen protector on that device.
Some screen protectors, when they're incorrectly installed
will make it so that the touch from the user
is not being pushed through to the digitizer.
This can happen if there is dirt or dust and debris
between the screen protector and the screen,
or if there are air bubbles inside of that screen protector
because it wasn't properly installed.
Another thing to rule out is any kind of a software issue.
So if you're using a smartphone or a tablet,
I recommend shutting it down completely, counting to 10,
and then turning it back on.
This way when the device reboots
all the software will be reloaded
and you can see if the device starts responding again.
If it does, this means there was an issue with the software
and it has since been rectified.
But if the issue is still there, you can now rule out
that it was a software problem,
and you can start looking at the hardware
of the digitizer itself.
Another thing to consider
when you're troubleshooting digitizers,
is to ask yourself the obvious question,
has anything changed?
That device just had its screen replaced
because somebody had dropped it,
then it's likely that somebody didn't reconnect
the digitizer to the motherboard.
And if this is the case,
that digitizer is no longer
going to be taking touch input and sending it to the processor
because there is no connection
between the digitizer and the motherboard.
So always ask yourself the obvious questions
and make sure things are connected to the right places
to ensure the signals are going where they need to.
The final mobile display issue we need to talk about
is calibration issues.
Now, if you're able to touch the screen
and things are happening,
but they're happening in the wrong places,
this is a calibration issue.
This can happen both with a mouse cursor,
which we call cursor drift, or with touch calibration issues
if you haven't properly configured the device.
So to be able to configure the device,
you need to go through the calibration routine,
which will normally bring up four to 10 different points
on the screen with little crosshairs
that you need to touch
to be able to recalibrate the display.
This way, it sees where you're touching,
versus where the display is,
and it can then on the software side,
reconfigure those things and account for any drift
that may be occurring from the digitizer.
Now, when it comes to cursor drift,
this can often occur because the touch pad sensitivity
is too high on that particular laptop.
Another reason for this is because when somebody is typing,
they're accidentally hitting that touchpad with their wrist
as they're typing on the keyboard.
This is because of the location of the touchpad
is right below the space bar on the keyboard.
I've had this happen
with several different models of laptops
I've had over the years,
and to be able to solve this,
some manufacturers actually allow you
to disable the touchpad while you're typing
by hitting a function and a special function key.
For instance, it might be Function F5
on your particular laptop,
and this will disable the touchpad while you're typing
and then when you're ready to use it again,
you can hit Function F5 and be able to turn it back on.
So for this reason,
anytime you're troubleshooting a cursor drift issue,
I want you to always check your touchpad sensitivity
and observe your user actually using the laptop,
because as you see how they're typing,
you may see that they're accidentally bumping the track pad
and causing the cursor to drift across the screen.
So remember, when it comes to mobile display issues,
there are four main categories,
broken screens, dim images, digitizer issues,
and calibration issues.