Mobile devices
⏱ ~3-min readAceMark Guide
What this topic is really about
A remote wipe lets an administrator send a command that erases the data on a lost or stolen mobile device, protecting corporate information from unauthorized access. Airplane mode only disables radios, Do Not Disturb silences notifications, and a screen rotation lock affects display orientation — none of them removes data from the device.
A laptop screen displaying vertical colored lines but working fine with an external monitor indicates a problem with the LCD panel or its ribbon cable.. Working fine on an external monitor isolates the GPU and OS as healthy — output is reaching the port.
See the mechanism
The issue is isolated to the laptop's screen because it works fine with an external monitor, indicating the GPU and OS are functioning properly. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.
An exam-style question, fully explained
A laptop screen displays vertical coloured lines but works fine with an external monitor. What is the most likely cause?
- Identify what the question tests: A laptop screen displays vertical coloured lines but works fine with an external monitor..
- Working fine on an external monitor isolates the GPU and OS as healthy — output is reaching the port.
- The problem is local to the laptop panel or the ribbon cable between the motherboard and the panel.
- A driver issue would affect both displays.
- Why it matters: The issue is isolated to the laptop's screen because it works fine with an external monitor, indicating the GPU and OS are functioning properly. The display driver would affect both the internal and external displays if it were the cause. Therefore, the most likely cause is damage to the LCD panel or its connecting ribbon cable.
Traps the examiner sets
- Many people may incorrectly assume the issue is with the GPU or display driver, but the fact that the laptop works with an external monitor rules out these possibilities.
- Some may think puncturing or freezing a swollen battery is safe, but it can actually cause a fire.
- Airplane mode only disables radios, Do Not Disturb silences notifications, and a screen rotation lock affects display orientation — none of them removes data from the device.
Test your recall
Answer each from memory — you'll see instantly whether you're right and why.
Run a focused 10-question mini-mock on Mobile devices and see it stick.
Practice more of this topic →