fixed : MacBook’s external monitor screen stays black

Question :

In my office, I am using an external monitor as my main screen for my MacBook Pro. Today, the screen didn’t respond when I connected my MacBook however : the screen stays black and nothing appears on-screen. So I opened up my MacBook and used the built-in screen to figure out what’s wrong, but so far I haven’t found any indication in the Displays Preference Panel that my MacBook even detects the second screen…

What can I do ?

 

Answer :

In such situations you should always do this first :

Remedy #1 :

  • make sure your monitor is switched ON
  • then hit the SPACE-bar on your external keyboard several times (maybe once, usually about 5 to 10 times…)
  • the monitor should now appear and show the inlog panel to unlock your screensaver
  • then login

if this works, you’re good, if not, try Remedy #2

NOTE : if you have a Benq monitor (especially the BL2420TP), try this first :

fixed : Benq monitor stays black when MacBook is switched on

Remedy #2 :

  • unplug all cables between the monitor and your Mac ( DisplayPort / Thunderbolt / HDMI / DVI / VGA  and also USB, UTP, FireWire and PowerAdapter )
  • shut down your monitor
  • shut down your MacBook
  • reconnect all cables and double-check if they’re properly connected on both the Mac and the monitor
  • switch on your MacBook
  • switch on your monitor

if this works, you’re good, if not, try Remedy #3

Remedy #3 :

  • on your MacBook, open Apple [main menu bar top-left] –> System Preferences
  • in the System Preferences window, select “Displays”
  • in the Display Preferences window, see if there is a button marked “Gather Windows” bottom right
  • if there is no “Gather Windows” button, press the ALT-key on your keyboard and a button marked “Detect Displays” appears ; click on it when it appears

if this works, you’re good, if not, try Remedy #4

Remedy #4 :

  • on your MacBook, open Apple [main menu bar top-left] –> System Preferences
  • in the System Preferences window, select “Displays”
  • in the Display Preferences window, see if there is a button marked “Gather Windows” bottom right
  • if there is a “Gather Windows” button, click on it
  • then you will see 2 Display Preference windows on your MacBook screen
  • select the Display Preference window that has 3 tabs on it marked “Display”, “Arrangement” and “Color” (not the window that has “Display” and “Color” only)
  • first, press the ALT-key on your keyboard and a button marked “Detect Displays” appears where the “Gather Windows”-button used to be ; click on it when it appears
  • if your monitor switches on, you’re good, if not…
  • click on the “Arrangement”-tab and in the next window put a checkmark at “Mirror Display”
  • if your monitor switches on now, uncheck the “Mirror Display” option again and close your MacBook… you should be good now…

if this didn’t work, try Remedy #5

Remedy #5 :

  • unplug all cables between the monitor and your Mac ( DisplayPort / Thunderbolt / HDMI / DVI / VGA  and also USB, UTP, FireWire and PowerAdapter )
  • shut down your monitor
  • shut down your MacBook
  • reconnect your Mac to your monitor using a different type of cable then you normally would choose (e.g. if you normally use a DisplayPort/Thunderbolt-cable, use an HDMI or DVI cable now)
  • switch on your MacBook
  • switch on your monitor
  • if your monitor wakes from sleep now, open Apple –> System Preferences
  • in the System Preferences window, select “Displays”
  • in the Display Preferences window, see if there is a button marked “Gather Windows” bottom right
  • if there is a “Gather Windows” button, click on it
  • then you will see 2 Display Preference windows on your MacBook screen
  • now, remove the monitor-cable that you have just used to connect your MacBook to your monitor
  • then, reconnect your MacBook to your monitor using all cables you normally use to connect the two
  • if your monitor now wakes from sleep, you’re good
  • if it doesn’t, restart your monitor
  • it that doesn’t help, restart your Mac

normally your issue should be resolved by now…

if still the monitor stays showing a back screen, I’m sorry to inform you that your screen probably has a hardware problem… if so, get an authorized Mac-repair-centre to fix it, get the Apple Store support-crew to fix this…

that’s it !

enjoy 😉