CompTIA A+
A+ Cheat Sheet
CompTIA A+ Is Broader Than You Think — Troubleshooting Methodology Is the Real Test
Hardware specs get you partial credit. Knowing the right troubleshooting sequence gets you the pass.
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Among the harder certs
Avg: Approximately 62–67%
Pass: 750 / 1000
Most candidates understand CompTIA A+ concepts — and still fail. This exam tests how you apply knowledge under pressure.
Core Framework
CompTIA A+ Troubleshooting Methodology (6 Steps)
A+ tests two exams: Core 1 (1101) for hardware, networking, virtualization; Core 2 (1102) for OS, security, software troubleshooting. The troubleshooting methodology appears across both — and the sequence matters in scenario questions.
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01
1. Identify the problem
— Gather info, question the user
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02
2. Establish a theory of probable cause
— Consider multiple causes
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03
3. Test the theory
— Confirm or revise
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04
4. Establish a plan of action
— Resolve with minimal impact
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05
5. Implement the solution
— Document changes
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06
6. Verify full functionality and prevent recurrence
Scenario Traps
Wrong instinct vs correct approach
A user's laptop won't charge
✕ Wrong instinct
Replace the battery immediately
✓ Correct approach
Follow the troubleshooting methodology: test with a known-good charger, check power settings, test the DC jack, then consider battery replacement as a later step
A workstation needs to be repurposed for a different department
✕ Wrong instinct
Format the drive and reinstall the OS
✓ Correct approach
Follow data destruction policy appropriate to data sensitivity: standard wipe for low-sensitivity data, secure erase or physical destruction for high-sensitivity data
Multiple users on the same network report slow internet
✕ Wrong instinct
Restart each user's computer
✓ Correct approach
Identify the common infrastructure element (switch, router, ISP), test connectivity at each layer, and check for bandwidth saturation or QoS misconfiguration
Quick Rules
Know these cold
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Always establish theory before testing — don't jump to solutions
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Document everything — efore, during, and after changes
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Data backup is required before any repair that risks data loss
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Check the simple/cheap fix first — ables, power, settings before hardware replacement
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Laser printer image quality issues — rum → toner → fuser in that diagnostic order
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Windows safe mode is the first step for OS-level malware removal
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Never open a CRT monitor — capacitors retain lethal charge even when unplugged
Self Check
Can you answer these without checking your notes?
In this scenario: "A user's laptop won't charge" — what should you do first?
Follow the troubleshooting methodology: test with a known-good charger, check power settings, test the DC jack, then consider battery replacement as a later step
In this scenario: "A workstation needs to be repurposed for a different department" — what should you do first?
Follow data destruction policy appropriate to data sensitivity: standard wipe for low-sensitivity data, secure erase or physical destruction for high-sensitivity data
In this scenario: "Multiple users on the same network report slow internet" — what should you do first?
Identify the common infrastructure element (switch, router, ISP), test connectivity at each layer, and check for bandwidth saturation or QoS misconfiguration
Failure Patterns
Common Exam Mistakes — What candidates get wrong
Skipping the theory step and going straight to fixes
The exam expects candidates to establish a probable cause before testing a solution. Jumping straight to replacing hardware is wrong when a simpler software or configuration fix is possible.
Confusing RAM symptoms with CPU or storage issues
Random crashes, BSODs, and application errors can indicate RAM failure, but they also indicate storage or overheating issues. The correct answer tests each systematically rather than replacing RAM immediately.
Misidentifying wireless standards and their capabilities
802.11ac (Wi-Fi 5) and 802.11ax (Wi-Fi 6) capabilities, frequency bands, and theoretical speeds are frequently tested. Mixing up 2.4GHz vs. 5GHz band characteristics causes scenario errors.
Ignoring data backup before making repairs
Before any repair that could cause data loss (especially storage-related), the exam expects backup verification as a required step. Skipping it is always wrong in A+ scenarios.
Applying consumer-level thinking to enterprise printer scenarios
A+ covers laser, inkjet, thermal, and impact printers. Enterprise scenarios involve printer pooling, security, and driver deployment. Calibration and maintenance kit intervals are tested.
A+ rewards systematic thinking over hardware memorization. Test whether you know the right sequence.