Mac screen issues — black, flickering, lines, spots and wrong colours
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Quick answer
Screen faults are often the most dramatic, but not always the most expensive to repair. First: test with an external display to separate the panel from the logic board. We repair displays on every Mac model, from simple flexgate cables to full Liquid Retina XDR replacements.
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Why is the screen black?
First: do you hear the Mac starting (fans, startup chime)? If yes, try turning brightness up (press F2 several times). If still black, plug in an external display via USB-C. If the external display works, the fault may be in the panel itself, the flex cable (typically flexgate on 2016-2017 Pro), or the internal display path on the logic board — all three are repairable with us. If the external display doesn't work either, it's definitely a logic board fault. See current pricing per model at macmo.dk/reparation.
Why does the screen flicker?
Flickering is typically caused by: 1) a faulty backlight driver, 2) a loose flex cable between display and logic board (open/close the lid — if the flicker follows the motion, it's the cable), 3) a software conflict (test in Safe Mode). If only certain apps flicker, it's software. If the entire system flickers, it's hardware.
Why is half the screen black?
Half-black screens are typically a faulty T-CON (Timing Controller) or flex cable. On Apple Silicon it can also be a driver fault after a macOS update — try booting in Safe Mode. If it's still there, it's hardware. Diagnosis with us is free.
Why are there lines on the screen?
Vertical or horizontal lines are almost always hardware — typically a broken flex cable or a faulty T-CON. Test with an external display to confirm the problem is in the panel itself. If the lines are also there during boot (Apple logo), it's definitely hardware.
Why are there spots on the screen?
Persistent dark or light spots are caused by: 1) pressure on the screen (from closing the MacBook with something on the keyboard), 2) dead pixels (factory defect or natural wear), 3) backlight failing in one area. Spots can't be repaired without replacing the display.
Why are the colours wrong?
Off colours: 1) check the colour profile in System Settings → Displays → Colour Profile. Choose 'Display P3'. 2) If only certain apps have wrong colours, it's app-specific. 3) If the entire screen is pink, yellow or green, it's a faulty backlight driver or GPU. Test with an external display.
Why does the screen blink?
A blinking screen (briefly going black for seconds) is typically a faulty GPU or driver conflict. Try: 1) restart, 2) update macOS, 3) Safe Mode, 4) clean install. If nothing helps, the GPU or logic board is faulty. On the older 15-inch Pro 2011 it's known as 'radeongate' and is often repairable.
Why doesn't the backlight work?
If you can faintly see the image with a strong flashlight against the screen, the backlight is faulty — not the LCD itself. It's typically a faulty LED driver or a broken backlight cable (part of the flex cable). The repair can be cable alone (DKK 1,500-2,500) or the whole display (DKK 1,900-3,500 on most MacBooks, DKK 6,000-8,000 on mini-LED Pro 14-inch/16-inch).
Why is the screen dark but the Mac is running?
It's the backlight — see the previous question. Test by turning brightness up to max and shining a flashlight at the screen in a dark room. If you can see a faint image, the LCD is fine and only the backlight is out. A less expensive repair than a full screen replacement.
Why doesn't an external display work?
Check: 1) the USB-C cable supports video (DisplayPort Alt Mode) — cheap charging cables do NOT. 2) The external display supports the input. 3) The adapter (HDMI/DisplayPort) is compatible with Mac. 4) On M1/M2 Air, only one external display can be connected (M3 Air can drive two in clamshell).
Why doesn't my Mac detect an external display?
1) Check cable and adapter, 2) restart both devices (Mac and display), 3) check System Settings → Displays — click 'Detect Displays' (hold Option), 4) NVRAM reset (Intel) or hard restart (Apple Silicon). If still nothing, the Thunderbolt controller may be faulty — contact us.