ACMT Display & Video Troubleshooting 2

Question 1

A MacBook's display has lines running vertically across the screen after a drop. What is the most likely cause?

Accepted Answer

Cracked display panel or damaged LCD flex cable

Answer

Vertical lines on the display after physical impact almost always indicate a cracked LCD panel or a damaged flex cable rather than a software issue.

Question 2

What is 'image retention' on a Mac display, and how is it typically addressed?

Accepted Answer

A temporary ghost image left on an LCD after displaying a static image; may clear with normal use or a display test

Answer

Image retention is a temporary phenomenon where a ghost of a previous image lingers on the LCD; running a white or grey screen for several minutes often clears it.

Question 3

Which Apple tool allows a technician to adjust display color profiles and run uniformity tests on a replacement iMac display?

Accepted Answer

AST 2 Display Diagnostics

Answer

AST 2 includes display diagnostic tests that check for backlight uniformity, color accuracy, and pixel defects following a display replacement on iMac and MacBook models.

Question 4

A MacBook Pro with a Retina display has bright white spots or 'blooming' around dark areas. What does this indicate?

Accepted Answer

Backlight bleed through the LCD layers, often from pressure or a failing display

Answer

Backlight bleed is light from the LED backlight leaking around the edges or through the LCD panel, commonly caused by physical pressure or a degrading display assembly.

Question 5

After replacing a MacBook display assembly, the technician notices the ambient light sensor is no longer adjusting brightness. What was most likely missed?

Accepted Answer

The ambient light sensor cable was not reconnected during the display replacement

Answer

The ambient light sensor has its own cable that must be reconnected when replacing a MacBook display assembly; missing this step disables automatic brightness adjustment.

ACMT - Apple Certified Macintosh Technician Practice Test

ACMT - Apple Certified Macintosh Technician Practice Test

ACMT Display & Video Troubleshooting 2