ACMT Display & Video Troubleshooting 1 — Questions and Answers
Question 1: A MacBook Pro's built-in display shows a pink or purple tint after replacement. What is the most likely cause?
- Incorrect color profile selected in System Settings
- Display data cable not fully connected or damaged (Correct answer)
- GPU failure on the logic board
- NVRAM needs to be reset
Correct answer: Display data cable not fully connected or damaged
A color tint on a replaced display is most commonly caused by a display data cable that is not fully seated or was damaged during the repair.
Question 2: Which test in Apple Service Toolkit 2 (AST 2) verifies that a replacement display is functioning correctly?
- Battery Health Test
- Display Test (including backlight and pixel tests) (Correct answer)
- Network Throughput Test
- SSD Speed Test
Correct answer: Display Test (including backlight and pixel tests)
AST 2 includes a Display Test that checks backlight uniformity, pixel defects, and color accuracy, which must be run after every display replacement.
Question 3: An iMac displays a blank screen but a startup chime is heard and the Mac responds to keyboard commands. What is most likely faulty?
- Logic board
- Display assembly or its connection to the logic board (Correct answer)
- SSD
- RAM
Correct answer: Display assembly or its connection to the logic board
If the Mac is booting and responding (evidenced by the chime and keyboard response) but no image is visible, the display assembly or its connection is the likely fault.
Question 4: What standard pixel defect policy does Apple use to determine if a built-in display replacement is warranted?
- Any single dead pixel qualifies for replacement
- Apple's bright or dark pixel policy, which defines acceptable thresholds before replacement (Correct answer)
- More than 10 dead pixels are required
- Dead pixels in the center only qualify
Correct answer: Apple's bright or dark pixel policy, which defines acceptable thresholds before replacement
Apple has a documented bright pixel and dark pixel policy that specifies the number and location of pixel defects that qualify a display for replacement under warranty.
Question 5: A customer connects an external display to their MacBook via USB-C, but no image appears. What should the technician check first?
- Whether macOS is up to date
- Cable compatibility and whether the USB-C port supports DisplayPort Alt Mode (Correct answer)
- Battery charge level
- Wi-Fi connection
Correct answer: Cable compatibility and whether the USB-C port supports DisplayPort Alt Mode
Not all USB-C cables support DisplayPort Alt Mode required for video output; verifying the cable and port support for video is the first troubleshooting step.
Question 6: Which keyboard shortcut detects and configures a newly connected external display on a Mac?
- Command + F2
- System Settings > Displays > Detect Displays (Correct answer)
- Option + Brightness key
- Control + Command + Q
Correct answer: System Settings > Displays > Detect Displays
Clicking 'Detect Displays' in System Settings > Displays forces macOS to scan for connected external displays when one is not recognized automatically.
ACMT Display & Video Troubleshooting 1
A MacBook Pro's built-in display shows a pink or purple tint after replacement.
What is the most likely cause?