- A
A tone generator and probe.
Why wrong: This is used to identify which cable goes where, not to test for faults.
- B
A multimeter.
Why wrong: A multimeter can test continuity but is less efficient than a dedicated cable tester for Ethernet cables.
- C
A cable tester.
A cable tester can check for continuity, shorts, and wiring faults, which is the first step in diagnosing a no-link issue.
- D
A time-domain reflectometer (TDR).
Why wrong: A TDR is more advanced and used for locating breaks or impedance issues, but a basic cable tester is sufficient for initial checks.
Question 771 of 1,020
First Tool for No Link Light: Cable Tester
This 220-1201 practice question tests your understanding of cabling. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A technician is troubleshooting a network drop that was working yesterday but now has no link light at the switch. The cable run is 80 meters and passes through a conduit. Which tool should be used first to isolate the problem?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"first"Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
Quick Answer
The answer is a cable tester. When troubleshooting a network drop with no link light, the most direct first tool is a cable tester because it can immediately identify physical faults like breaks, shorts, or miswiring that would prevent a link from establishing. In this scenario, the 80-meter run through a conduit introduces potential for physical damage, and a cable tester isolates the problem faster than any other tool. On the CompTIA A+ Core 1 220-1201 exam, this question tests your ability to prioritize basic troubleshooting steps—a common trap is reaching for a tone generator or multimeter first, but those are for tracing cables or measuring voltage, not for verifying continuity. Remember the memory tip: “No link? Think link—cable tester first.”
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 cable tester.
Option C is correct because a cable tester (often a wiremap tester) is the first tool to use when verifying basic connectivity and physical layer issues like broken wires, shorts, or miswiring. Since the link light is absent and the cable was working before, the most likely cause is a physical fault in the 80-meter run, and a cable tester can quickly confirm continuity and pinout without requiring advanced diagnostics.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
A tone generator and probe.
Why it's wrong here
This is used to identify which cable goes where, not to test for faults.
- ✗
A multimeter.
Why it's wrong here
A multimeter can test continuity but is less efficient than a dedicated cable tester for Ethernet cables.
- ✓
A cable tester.
Why this is correct
A cable tester can check for continuity, shorts, and wiring faults, which is the first step in diagnosing a no-link issue.
Clue confirmation
The clue word "first" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
A time-domain reflectometer (TDR).
Why it's wrong here
A TDR is more advanced and used for locating breaks or impedance issues, but a basic cable tester is sufficient for initial checks.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often jump to a TDR (Option D) because they think of distance-to-fault for a long run, but the question asks for the first tool to isolate the problem, and a simple cable tester is faster and more appropriate for verifying basic connectivity before using specialized equipment.
Detailed technical explanation
How to think about this question
A basic cable tester sends pulses down each pair and checks for proper pin-to-pin continuity, shorts, opens, and miswires (e.g., split pairs). For a 80-meter run, even a small break or a single faulty termination can prevent the switch from establishing a link, as Ethernet requires all four pairs (for 1000BASE-T) or at least two pairs (for 100BASE-TX) to be intact and correctly wired. In real-world scenarios, a cable tester is the first line of defense because it immediately rules out physical layer issues before moving to more complex diagnostics like TDR or fluke testing.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 220-1201 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Quick reference
OSI Model Reference
| Layer | Name | PDU | Key Protocols / Devices |
|---|---|---|---|
| 7 | Application | Data | HTTP, HTTPS, DNS, SMTP, FTP, SSH |
| 6 | Presentation | Data | TLS / SSL, JPEG, ASCII encoding |
| 5 | Session | Data | NetBIOS, RPC, SIP |
| 4 | Transport | Segment / Datagram | TCP, UDP |
| 3 | Network | Packet | IP, ICMP, OSPF — Routers |
| 2 | Data Link | Frame | Ethernet, Wi-Fi, PPP — Switches, Bridges |
| 1 | Physical | Bits | Cables, NICs, Hubs, Repeaters |
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Cabling — study guide chapter
Learn the concepts, then practise the questions
- →
Cabling practice questions
Targeted practice on this topic area only
- →
All 220-1201 questions
1,020 questions across all exam domains
- →
CompTIA A+ Core 1 220-1201 study guide
Full concept coverage aligned to exam objectives
- →
220-1201 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 220-1201 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Mobile Device Hardware Servicing practice questions
Practise 220-1201 questions linked to Mobile Device Hardware Servicing.
Mobile Device Connection Methods practice questions
Practise 220-1201 questions linked to Mobile Device Connection Methods.
Mobile Device Accessories practice questions
Practise 220-1201 questions linked to Mobile Device Accessories.
Mobile Device Network Connectivity practice questions
Practise 220-1201 questions linked to Mobile Device Network Connectivity.
Mobile Device Application Support practice questions
Practise 220-1201 questions linked to Mobile Device Application Support.
Network Protocols practice questions
Practise 220-1201 questions linked to Network Protocols.
TCP & UDP Ports practice questions
Practise 220-1201 questions linked to TCP & UDP Ports.
Wireless Networking Technologies practice questions
Practise 220-1201 questions linked to Wireless Networking Technologies.
Network Services practice questions
Practise 220-1201 questions linked to Network Services.
Network Configuration Concepts practice questions
Practise 220-1201 questions linked to Network Configuration Concepts.
Common Networking Hardware practice questions
Practise 220-1201 questions linked to Common Networking Hardware.
IP Addressing practice questions
Practise 220-1201 questions linked to IP Addressing.
Practice this exam
Start a free 220-1201 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 220-1201 question test?
Cabling — This question tests Cabling — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: A cable tester. — Option C is correct because a cable tester (often a wiremap tester) is the first tool to use when verifying basic connectivity and physical layer issues like broken wires, shorts, or miswiring. Since the link light is absent and the cable was working before, the most likely cause is a physical fault in the 80-meter run, and a cable tester can quickly confirm continuity and pinout without requiring advanced diagnostics.
What should I do if I get this 220-1201 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "first". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more ways this is tested on 220-1201
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A technician is troubleshooting a network drop that was working yesterday but now has no link light. The cable run is 90 meters and uses Cat5e. The patch cables and switch ports have been tested and are fine. What is the most likely issue?
medium- A.The cable is too long for Cat5e.
- ✓ B.The cable has been cut or damaged.
- C.The network switch is not powered on.
- D.The cable is terminated with the wrong standard.
Why B: Since the cable run is 90 meters (within the 100-meter maximum for Cat5e), the patch cables and switch ports are verified working, and the link light is absent, the most likely cause is physical damage to the cable—such as a cut, pinch, or break—that interrupts the electrical continuity required for link pulses. A damaged cable prevents the switch and NIC from establishing a link, even if all other components are functional.
Keep practising
More 220-1201 practice questions
- During a network cable installation, a technician needs to verify that a newly run Cat6 cable is properly terminated and…
- A user connects a 4K monitor to their laptop using a USB-C port. The monitor is detected, but the resolution is stuck at…
- A technician is troubleshooting a laptop that will not charge. The battery is removable, and the power adapter works on…
- A customer brings in a smartphone with a broken charging port. They want the port replaced. During disassembly, the tech…
- A user reports that their laptop's keyboard types random characters when certain keys are pressed. The laptop has not be…
- A technician is troubleshooting a laptop that shuts down randomly after a few minutes of use. The fan is spinning, and t…
Last reviewed: Jul 4, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.