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 😉