ACMT macOS Troubleshooting

Question 1

A customer's Mac gets stuck on the gray loading bar during startup. Which startup mode should the technician try first?

Accepted Answer

Safe Mode

Answer

Safe Mode (holding Shift at startup) disables third-party extensions and performs a directory check, making it the first troubleshooting step for startup hang issues.

Question 2

Which command in macOS Terminal is used to repair disk permissions on an HFS+ volume in Recovery Mode?

Accepted Answer

fsck -fy /dev/disk0

Answer

The command 'fsck -fy /dev/disk0' (with the correct disk identifier) is used in single-user or Recovery Mode to check and repair the file system.

Question 3

What does the 'Prohibitory Symbol' (circle with a slash) at startup indicate on a Mac?

Accepted Answer

macOS cannot find a valid, compatible system folder to boot from

Answer

The prohibitory symbol means the Mac found a startup disk but cannot use it, usually because macOS is missing, corrupt, or incompatible with the hardware.

Question 4

How does a technician boot a Mac to macOS Recovery on an Apple Silicon Mac?

Accepted Answer

Hold the power button until 'Loading startup options' appears

Answer

On Apple Silicon Macs, holding the power button until 'Loading startup options' appears is the correct way to enter recoveryOS.

Question 5

A customer reports that their Mac keeps crashing with a kernel panic. Where should the technician look for clues about the cause?

Accepted Answer

Console app > Crash Reports / System Diagnostics

Answer

The Console app's Crash Reports and System Diagnostics sections contain kernel panic logs (panic.ips files) that identify the crashing process or driver.

ACMT - Apple Certified Macintosh Technician Practice Test

ACMT - Apple Certified Macintosh Technician Practice Test

ACMT macOS Troubleshooting