easyMultiple Choice
220-1201 Practice Question: That their laser printer is producing pages with…
A user reports that their laser printer is producing pages with vertical black streaks. The streaks appear consistently in the same location on every page. Which printer component is most likely causing this issue?
⚠ Common exam trap
220-1201 often tests the ability to distinguish between drum, toner, and fuser symptoms; candidates may incorrectly blame the toner cartridge for vertical streaks when the drum is the actual cause.
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
✓
Drum unit
Vertical black streaks that appear in the same location on every page are typically caused by a scratched or contaminated drum unit. The drum transfers toner to the paper, and any damage or debris on its surface creates a repeating mark at the corresponding position on each page.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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Fuser assembly
Why it's wrong here
The fuser assembly's primary function is to permanently bond the toner to the paper using intense heat and pressure. A malfunction in this unit, such as a damaged heating element or pressure roller, typically results in toner smudging, ghosting, or toner that easily flakes off the page because it hasn't been properly fused. While it can also cause paper jams, it does not create consistent vertical streaks, as those defects originate earlier in the image formation process.
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Toner cartridge
Why it's wrong here
A toner cartridge primarily supplies the toner powder used for printing. If the cartridge itself is defective or leaking, it might release toner randomly, causing scattered spots, splotches, or a generally dirty background on the printout. However, the toner cartridge, separate from the integrated drum unit in some designs, does not typically cause consistent, repeating vertical streaks, as these are usually indicative of a physical defect on the imaging drum's surface.
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Drum unit
Why this is correct
The drum unit, or photoconductive drum, is the central component responsible for forming the electrostatic image and attracting toner. If the delicate photosensitive surface of the drum is scratched, worn, or has a foreign particle adhering to it, that specific defect will consistently pick up or repel toner in the same location during each rotation. This consistent defect is then transferred to the paper, manifesting as a persistent vertical streak or line down every printed page.
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Pickup roller
Why it's wrong here
Pickup rollers are mechanical components designed to reliably feed individual sheets of paper from the paper tray into the printer's internal path. When these rollers become worn, dirty, or lose their friction, they fail to grip the paper effectively, leading to common paper feed issues such as jams, misfeeds, or multiple sheets being pulled simultaneously. Since their function is solely paper handling, they do not directly influence the toner application or image creation process, and therefore cannot cause print quality defects like vertical streaks.
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This 220-1201 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 220-1201 exam.