220-1101 Hardware and Network Troubleshooting Practice Question
A technician is troubleshooting a laptop that will not display an image on its built-in screen. When the power button is pressed, the power LED turns on, the fan spins, and the technician can hear the Windows startup sound. Connecting an external monitor via HDMI shows the desktop correctly. The technician has already tried adjusting the screen brightness using the function keys, but there is no change. The laptop was working normally yesterday and was not dropped. Which of the following components is MOST likely faulty?
⚠ Common exam trap
It's easy for candidates to assume a blank screen with power-on signs means a dead GPU or motherboard, but the external monitor test proves the GPU is fine — the CompTIA 220-1101 exam specifically tests the ability to isolate display faults to the LCD cable or inverter when external video works.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The LCD cable connecting the motherboard to the display
The LCD cable (eDP or LVDS ribbon) connects the motherboard to the built-in display panel. Since the external monitor works perfectly via HDMI, the GPU is fully functional and generating video output. The fact that the power LED, fan, and Windows startup sound are all normal confirms the system boots successfully, isolating the fault to the internal display path — most commonly the LCD cable, which can fail due to flexing, pin damage, or a loose connection even without physical trauma.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The LCD cable connecting the motherboard to the display
Why this is correct
The LCD cable is the sole link between the motherboard and the internal panel, carrying differential video signals (eDP or LVDS) and backlight power. If it works loose at either end—especially after hinge stress or disassembly—the panel receives no data and stays black, while the GPU can still drive an external monitor through its separate output. That is why this is the correct answer.
- ✗
The graphics processing unit (GPU) on the motherboard
Why it's wrong here
The GPU renders all graphics and feeds both the internal LCD and any external display through independent output paths. If the GPU were truly faulty, the external monitor would either show no image, display corruption, or fail to initialize entirely—it would not work perfectly. Since the external monitor is functional, the GPU is clearly alive, so this cannot be the cause.
- ✗
The DC jack or power adapter
Why it's wrong here
The DC jack and power adapter only supply electrical power; they have no role in video generation or signal routing. The laptop's ability to power on, spin the fan, and play startup sounds proves that the motherboard is receiving adequate power. A failing jack or adapter would cause the entire system to shut down or fail to boot, not selectively black out the internal display.
- ✗
The hard drive or SSD
Why it's wrong here
The hard drive or SSD only stores the OS and programs; it does not produce or transmit video signals. Because the laptop boots successfully and the user hears Windows startup sounds, the storage device is functioning and the OS is loading. A failed drive would typically cause a boot failure with an error screen or beep code, not a blank internal LCD with otherwise normal operation.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1101 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1101 exam.