ACMT macOS Troubleshooting 2 — Questions and Answers
Question 1: What does running 'First Aid' in Disk Utility do?
- Erases the disk
- Verifies and repairs the disk's file system structure (Correct answer)
- Formats the drive as APFS
- Checks hardware health of the SSD
Correct answer: Verifies and repairs the disk's file system structure
First Aid in Disk Utility verifies the file system structure and repairs directory issues on HFS+ and APFS volumes without erasing user data.
Question 2: A Mac shows a flashing question mark folder at startup. What does this indicate?
- FileVault encryption is active
- The startup disk cannot be found or is not set (Correct answer)
- RAM has failed
- The Mac has entered Target Disk Mode
Correct answer: The startup disk cannot be found or is not set
A flashing question mark folder means the Mac cannot find a valid startup disk, either because the SSD has failed, macOS is missing, or the startup disk setting is incorrect.
Question 3: Which macOS utility allows a technician to create a bootable macOS installer on a USB drive?
- Disk Utility
- createinstallmedia command-line tool (Correct answer)
- Apple Configurator 2
- Migration Assistant
Correct answer: createinstallmedia command-line tool
The 'createinstallmedia' command-line tool, included in the macOS installer app, is used to create a bootable USB installer drive.
Question 4: A user's Mac is running slowly and Activity Monitor shows high kernel_task CPU usage. What is the most likely cause?
- A virus infection
- The Mac is throttling the CPU due to thermal or power issues (Correct answer)
- RAM is faulty
- The SSD is full
Correct answer: The Mac is throttling the CPU due to thermal or power issues
High kernel_task CPU usage is typically macOS's thermal management intentionally reducing CPU performance to protect hardware from overheating.
Question 5: What is the function of NVRAM (Non-Volatile RAM) on a Mac?
- Stores user documents for quick access
- Stores settings like startup disk, display resolution, and speaker volume (Correct answer)
- Holds the macOS kernel during boot
- Manages active RAM allocation
Correct answer: Stores settings like startup disk, display resolution, and speaker volume
NVRAM stores small amounts of data that need to persist when the Mac is off, including startup disk selection, time zone, and display settings.
Question 6: How should a technician reset NVRAM on an Intel-based Mac?
- Hold Command + R at startup
- Hold Option + Command + P + R at startup for at least two startup chimes or 20 seconds (Correct answer)
- Remove and reinsert the CMOS battery
- Run 'nvram -c' in Terminal
Correct answer: Hold Option + Command + P + R at startup for at least two startup chimes or 20 seconds
Holding Option + Command + P + R during startup for two chimes or 20 seconds resets NVRAM on Intel Macs.
ACMT macOS Troubleshooting 2
What does running 'First Aid' in Disk Utility do?