easyMultiple ChoiceObjective-mapped
220-1201 Practice Question: A customer reports that their desktop PC emits a…
A customer reports that their desktop PC emits a series of three long beeps and then nothing appears on the screen. The system was working fine yesterday. What is the most likely cause of this issue?
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
✓
Loose or failed RAM module
Three long beeps during POST typically indicate a memory (RAM) failure. This is a common POST code for many BIOS manufacturers, and reseating or replacing the RAM modules is the first troubleshooting step. The beeps are a diagnostic signal from the motherboard that the system cannot proceed without functional memory.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Faulty power supply unit
Why it's wrong here
A faulty power supply unit (PSU) typically manifests as a complete lack of power to the system, preventing the computer from turning on, or causing intermittent power failures. While a severely failing PSU might lead to erratic behavior, it generally does not produce specific, standardized BIOS beep codes. These codes are generated by the motherboard's BIOS/UEFI during the Power-On Self-Test (POST), which requires stable and sufficient power to even begin execution. Therefore, a PSU issue usually prevents POST from running effectively enough to emit diagnostic beeps.
- ✓
Loose or failed RAM module
Why this is correct
Three long beeps are a widely recognized Power-On Self-Test (POST) error code, specifically indicating a problem with the system's Random Access Memory (RAM). During POST, the BIOS/UEFI performs initial hardware checks, and if it fails to detect or properly initialize the RAM modules, it will signal this critical error via a series of audible beeps. This could be due to a module being improperly seated, a faulty RAM stick, or an issue with the memory slot itself, preventing the system from loading the operating system.
- ✗
Overheating CPU
Why it's wrong here
An overheating Central Processing Unit (CPU) typically triggers protective mechanisms within the system, such as thermal throttling to reduce performance or an emergency shutdown to prevent permanent damage. While these are critical issues, CPU overheating usually occurs after the Power-On Self-Test (POST) has completed or during system operation, not as a condition that generates specific POST beep codes. BIOS beep codes are diagnostic signals for hardware failures detected *before* the system fully boots, whereas overheating is a dynamic thermal management concern.
- ✗
Corrupted operating system files
Why it's wrong here
Corrupted operating system (OS) files are a software issue that prevents the OS from loading correctly after the Power-On Self-Test (POST) has successfully completed. BIOS beep codes, however, are diagnostic signals generated by the motherboard's firmware during POST, which occurs *before* any attempt to load the operating system. Therefore, issues with OS files, such as a corrupted boot sector or missing system libraries, cannot cause the system to emit POST beep codes, as these problems manifest much later in the boot sequence.
Go deeper
Related to this question
About these practice questions
One of 972 original 220-1201 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.