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 in the same position on every page. What is the most likely cause?
⚠ Common exam trap
220-1201 often tests the difference between drum, corona wire, and fuser issues; candidates may confuse vertical streaks with corona wire problems, but corona wire issues typically cause horizontal streaks or smudges.
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
✓
A scratched drum
Vertical black streaks that appear in the same position on every page are typically caused by a scratched or damaged drum (C). The drum is a cylindrical component that transfers toner to the paper; scratches or debris on the drum cause repetitive marks at the same location on each page. Replacing the drum unit resolves the issue.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Low toner cartridge
Why it's wrong here
A low toner cartridge typically results in print that appears faded, light, or patchy across the entire page, or in specific areas where toner is depleted. It does not cause distinct, repeating solid black streaks because there isn't an excess of toner being deposited in a consistent pattern; rather, there's insufficient toner available for proper image formation.
- ✗
A dirty corona wire
Why it's wrong here
A dirty primary corona wire (or charge roller) impairs its ability to uniformly apply a negative electrostatic charge to the photosensitive drum. This often leads to areas on the drum that are not properly charged, resulting in vertical white streaks where toner is repelled, or a generally faded print due to insufficient toner attraction, rather than depositing excess black toner.
- ✓
A scratched drum
Why this is correct
A scratch on the photosensitive drum permanently damages its light-sensitive coating. This damaged area will consistently attract toner, even in regions where it should be repelled, and then transfer that excess toner to the paper during each rotation. This repeated transfer of toner from the fixed scratch location results in distinct, consistent vertical black streaks appearing at regular intervals down the printed page.
- ✗
A faulty fuser
Why it's wrong here
The fuser assembly is responsible for melting and permanently bonding the toner to the paper using heat and pressure. A faulty fuser, such as one with an incorrect temperature or pressure, would typically cause toner to smear easily, flake off, or appear dull because it hasn't been properly fused. It does not create distinct, repeating black streaks, as the issue lies in the bonding process rather than the initial toner deposition pattern.
Visual reference
Go deeper
Related to this question
About these practice questions
This 220-1201 question is part of Courseiva's 871-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
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.