Why won't my MacBook detect an external display?

  • Problem
  • Updated 2 years ago
About 50% of the time, my MacBook doesn't detect an external display. I put it to sleep when leaving the office, possibly use it at home that evening, and the next morning when I return to my desk and connect it to a monitor, it doesn't detect. The "detect displays" command it of no help and a reboot is the only solution I've found.
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Dan Harrelson

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  • frustrated

Posted 8 years ago

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Al Yanes

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I have similar problems. My MacBook is only 3 months old and it won't detect external monitors. I have tried using the mini display to VGA and also the Mini Display to HDMI. Tried with my Samsung TV and with a 17" computer monitor and still the same problem. The VGA cable worked with a PC, so is not the VGA cable. The monitors do not detect a signal and the Macbook does not detect the monitors. I tried everything mentioned on this post with not luck. Any idea.
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enricorpg

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I had a similar problem and now I have found the fix. I bring back my mini DP to VGA adapter to the store and get a new one. That fixed the problem completely. Just to let you know, the adapter came with 1 year warranty, so it might not be too late to try this.
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hawesinsky

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Don't forget to click on the "Turn on Mirroring" command. (I did!)
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brwatts

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I bought a new adapter too and that fixed the problem. I had a Monoprice adapter, that worked for a few weeks, but it quite working. I replaced it with an Apple adapter and it's working great again.
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Al Yanes

  • 72 Points
My problem was that I was not plugging in the minidisplay all the way in. I guess this being my first Apple computer I thought that the plug was kind of small and I was affraid to break it. I tried this right after I wrote my comment on this site and it worked.
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Justin Herrick

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I'm trying to connect my macbook (late 07 model) to my new Dell ST2010 HD display.

It worked great when i first got it (yesterday) put the computer to sleep and shut the monitor off lastnight, but now today nothing.

Tried everything, i can't get the firmware update from apple, they seem to be having issues with their site.
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Frank Anthony

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I was in Malaysia when I encountered this problem with my brand new MacBook Pro 13", but didn't have the luxury of going to my local Apple Outlet to fix it, so I stayed up late to call the US and figure out how to fix it. My laptop worked when I initially plugged it into the LCD in my hotel room, but then I forgot it on battery and it went to sleep, to never work again until now. Your MacBook will get confused when this happens and it saves this in cache, so you've got to clear it like this.

1. Turn off your laptop, hold Shift + Control + Option and then Power (Note: it doesn't look like anything is happening but it is, ie.) you won't see anything and Mac will not start)
2. Laptop should still be off, then hit Command + Option + R + Power. Still holding these down when you see the Apple logo appear, press down P. You should hear the Apple chime twice and then you can let go.
3. Shut down your laptop, make sure it's pugged into A/C and your external monitor is connected. Press Power + Shift at the same time, which should start you off in Safe Mode and you should see your external display come on also.
4. Now you can restart your machine normally and it should all work for you.

Note: Remember to have your laptop plugged into AC anytime you connect to an external display and turn your power settings to Never under AC as well. When you disconnect, remove the External plug and wait 10 sec, before shutting down or closing your laptop.
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Dan Frederick Pitts

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if this works, I would LOVE to know why it's not mentioned on the thread that apple has archived and claimed success. APPLE DID NOT HELP US. Frank Anthony and a combined total of about 300 man-hours of labor... thanks Apple.
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Dan Frederick Pitts

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nope nope nope nope. this does NOT solve the problem. followed these instructions verbatim. If this is a hardware malfunction I think there should be a class action lawsuit and someone should investigate WHO has been suggesting on ALL these different websites that going and buying the "Apple" brand name Mini Display to DVI adaptor is the solution. Because it sure seems like Apple is probably selling those things, and probably have an interest in getting rid of them (isn't there a new video jack format already?) Even if it's accurate... Apple could say so instead of refusing to allow any more comments in their thread on this.
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kraft.ronny

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Reseting the pram didn't work unfortunately (as frank described).

My macbook connected to my insignia tv beautifully and easily the first couple of times and then BAAM, no dice. I've tried everything. rebooting, unplugging, blowing on it, calling insignia customer service, and nothing works. I've tried every resolution possible.

please please help.
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James Blane

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Same problem windows
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eddieflusa

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Same here.
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kraft.ronny

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turns out my roommate had actually ruined the cable by trying to stick it in the wrong jack on his own computer. got another one and now it all works fine.
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Andre Ramello

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I do have the same problem. Before Leopard, everything worked great... But since I updated the OSX my macbook 13" cant detect any display. That's very frustrating, cause I need that function to work.
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Andre Ramello

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I mean, since snow leopard
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Kyle

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From what I understand it could be the monitor. Because of the output from the screen is Either Digital or Analog (i cant remember) so through the Dongle/adapter it has to change it. I am not sure if you disrupt the signal it might not aquire it corectly the next time you try to go use it thats why you have to restart. Are any of you using DVI? Because that has the same signal i think its digital (dont quote me)
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Steve

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three lap tops in my house a $400 hp a $1200 dell and a $2700 Mac Book pro
they all work great with my view sonic monitor except the mac reading this thread to the end it looks like well over a year and still the same problem my Mac is only 3 months old will take it back demand a refund simple problem and no fix in sight
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enricorpg

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Did you try other adapters? My problem was my adaptor, it was faulty. Try it out with another adapter.
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Kyle

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I spent a good long while on the phone with Apple support which I am not pleased with for multiple reasons, however that happened to me once and they said some of the older displays wont work on the newer macs beacuse of the output of the computer is analog and the screen is digital (might have got it backwards) So to sum it up I don't believe there really is a fix other than get a new monitor or resort back to old laptop. You however can go to the apple store and see if they have a converter from digital to analog or vis versa. (i dont think they do)
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enricorpg

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Maybe what you meant was the computer's output is digital, and the monitor's input has to be analog. With the mini display port to VGA adapter, this should be able to work. They're about $30 I think (or around $10 in ebay). I wonder what monitor you have, but I've tried plugging my laptop to 5-6 different displays (some are older than 6 years old) and they seem to be working after I exchange my adapter.
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Kyle

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Yeah however some of the older monitors wont support it. Give apple a call thats what they will tell you. I even tried one of the mini display port vga adapters with my new macbook and it didn't work with my old dell screen (one of the first flat screens) However it did work on my old laptop. I have tried multiple adapters and multiple screens even multiple macbooks they all did the same thing. I am not really sure what to say because from what I got from the 3 different represenitives from apple there was no way I could get my screen to work. And it was because of how it was converting analog to digital.

This seems like Apple never really found a fix for it and brushed it off as old equipment.
I have a MacBook Pro less than 2 years old and 2 x 23 in Apple Cinema HD displays, both of which worked perfectly with the MacBook until recently. I suspect that this is an OSX Hardware/Software combo problem as the monitors still work fine with my old MacBook running the same OS rev. When I plug a display into the Pro, the Pro's screen goes blue indicating that the external display is being detected, but that's as far as it gets. What is it with Apple that they seem to struggle with the notion of after sales service - this isn't the first problem I've seen go unresolved and generally unanswered but i's getting very close to being my last...
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perezoso

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It seems to me Apple is leaving the door wide open for a class action law suit ... how many people are suffering agravation (and losses) with the very old issue of not being able to use their displays because the computers refuse to detect them? Obsolescence by design? It's been two years or more since the "problem" started and Apple does not provide an answer ... or a solution...
Enough is enough, I never agreed when I got my computer to dispose of it after some time or make a paper weight with it ....
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Dan Frederick Pitts

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I've got a 15" Macbook Pro i7 with an HP w1858 that came with the new machine my father purchased 4 months ago at sam's club. These are BOTH new.
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Dennis Brewer

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I'm upset over this. I love my MacBook, it's 3 this year and has been a fine machine. It's rugged and intuitive to use. I was so impressed I bought the Desk top switching completely to MAC from the Microsoft brand. All told about 3200. Today I thought, I need a monitior as the screen on the laptop is a bit small and I spend a lot of time online. But first i thought I'd google it and how it works and I find this. Come on Apple, if you can't find a fix in software (which I find hard to believe as it must have been fine when users had 10.4) then at least post a answer here!
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scott

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experiencing similar issue with my Macbook Pro 5.3, using OSX 10.6.6.:
I cannot get the display to fix on the screen -- I need to scroll up to top to see menu bars, and scroll to bottom to see dock. Computer thinks that external display is still attached?
Tried the following:
No on/off overscan available.
No on/off mirroring available.
Trying different sequences of rebooting with and without external Samsung 2HDMI monitor attached to repair problem. Tried to reset default display. No luck.
Rebooted with Control P+R.
Changing screen options.

All sequences failed to cure the issue.
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scott

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I should add - I've been using the external monitor without a problem for 1 year. This happened very suddenly while I was connected. I have the impression that I pressed a combination of keys to make this happen....

Thinking: handicap view option; incorrect sensing that external display is connected.

I should be able to fix this without having to worry about whether external display is connected or not
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scott

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Solution:

Command + Option + 8

you remove screen Zoom and voilĂ !
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scott

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Command + Option + 8
enable you to see Menu bar and dock (shrinks screen back to normal - not handicapped/vision impaired - size
I just bought a 13" Macbook pro last week, and today when I brought it into work, it would not detect the projector. I've tried other projectors at work, tried connecting it to a screen at home. Nothing.

Any solution?

Maybe I should just return the machine...?
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faran49

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same idea here,
i got a new macbook pro and at first it could detect my display
it had a bit of trouble after the recent update that was suppose to fix the bugs with displays,
but as of now, it can't detect the monitor altogether.
this is a shame,
day by day i'm losing hope in apple.