IMac External Monitor stopped working

I have an Intel based iMac and have been running my old 17inch apple monitor as a second display for over a year now. For no apparent reason today the monitor stopped working. The screen just appears black. there is power getting to it as the power light is on and the computer detects the display fine. I can even move objets to that monitor, I just cant see anything. Any helps would be appreciated.
thanks
Joe

Yep, have the same problem using a 3rd party cablesson mdp-hdmi adapter. Everything worked fine until quite recently. I have tried pretty much everything to fix it but nothing seems to work. I'm almost convinced it's an OS problem, as everything works fine when I boot into my windows bootcamp partition.
Apple, please get this sorted! I'm reluctant to shell out $35 only to find that I have the exact same problem with the official adapter. Though I probably will anyway because I urgently need to get my display working again.

Similar Messages

External monitor stopped working after 10.6.7 update

I have a MacBook Pro, model identifier MacBookPro6,2 with an NVIDIA GeForce GT 330M.
When I updated last night from 10.6.6 to 10.6.7 I stopped being able to use my Dell S2409W external monitor.
I have tried resetting the pram, resetting the SMC, booting with extensions off.
When I plug in the cable to the external monitor the Mac screen goes blue for about 0.5 second and re-appears but nothing displays on the external monitor; a second monitor is not listed in the Display preferences and the monitor reports that it is not receiving a signal.
I don't see anything in the system.log when I plug or unplug the monitor cable (I'm not sure if I should).
At random intervals while the external monitor cable is plugged in the screen goes blue for a half second and then re-appears.
The screen does not go blue if I wiggle or flex the monitor cable.

I see this in the windowserver.log after reboot, login with shift-key, and the external monitor connected.
There might be a clue here but I don't have anything to compare it to since I haven't collected these data when the external monitor was working.
I'd be curious to see the same data from the windowserver.log for somebody else with a MacBook Pro with an external monitor connected that does work.
You can view this log with the console application located: /Applications/Utilities/console.
If you are willing to share these data please reboot, and hold the shift-key down when logging in to disable extensions (thanks). If you look at the time just when the desktop appears when you end up looking at the windowserver.log you'll be able to see the windowserver starting up about 10 seconds prior to this time.
Mar 22 21:31:26 [110] Server is starting up
Mar 22 21:31:27 [110] CGXMappedDisplayStart: Display0 : boot screen
Mar 22 21:31:27 [110] CGXMappedDisplayStart: Display0 : display alias 0x0 valid
Mar 22 21:31:27 [110] CGXMappedDisplayStart: Display1 : no display alias property
Mar 22 21:31:27 [110] CGXMappedDisplayStart: Display2 : display alias 0x0 valid
Mar 22 21:31:27 [110] MPFinalizeInitialization: Display 0x3f003e unit 2 alias mask 0x5
Mar 22 21:31:27 [110] MPFinalizeInitialization: Display 0x4272dc0 unit 0 alias mask 0x5
Mar 22 21:31:27 [110] GLCompositor: GL renderer id 0x01022612, GL mask 0x00000003, accelerator 0x00003137, unit 0, caps 0x00000003, vram 512 MB
Mar 22 21:31:27 [110] GLCompositor: GL renderer id 0x01022612, GL mask 0x00000003, texture units 8, texture max 8192, viewport max {8192, 8192} extensions 0x0000000f
Mar 22 21:31:27 [110] GLCompositor: GL renderer id 0x01024300, GL mask 0x00000004, accelerator 0x00003c0b, unit 2, caps 0x00000003, vram 288 MB
Mar 22 21:31:27 [110] GLCompositor: GL renderer id 0x01024300, GL mask 0x00000004, texture units 8, texture max 8192, viewport max {8192, 8192} extensions 0x0000000f
Mar 22 21:31:27 [110] agc_attach: gMux mode is dynamic
Mar 22 21:31:28 [110] CGXPerformInitialDisplayConfiguration
Mar 22 21:31:28 [110] Display 0x4272dc0: MappedDisplay Unit 0; Vendor 0x610 Model 0x9cb7 S/N 0; online enabled built-in (0,0)[1680 x 1050], Rotation 0, base addr 0x102a00000
Mar 22 21:31:28 [110] Display 0x4272dc2: MappedDisplay Unit 2; Vendor 0x610 Model 0x9cb7 S/N 0; offline enabled built-in (2704,0)[1 x 1], Rotation 0, base addr 0x113800000
Mar 22 21:31:28 [110] Display 0x3f003d: MappedDisplay Unit 1; Vendor 0xffffffff Model 0xffffffff S/N -1; offline enabled (2705,0)[1 x 1], Rotation 0, base addr 0x102a00000
Mar 22 21:31:28 [110] Display 0x4272dc0: MappedDisplay Unit 0; ColorProfile "Color LCD" (MD5 a23cb9c96f2fd096b7a058db0d319259)
Mar 22 21:31:28 [110] kCGErrorIllegalArgument: CGXSetWindowListTags: Operation on a window 0x2 not owned by caller (PID 202)
Mar 22 21:31:35 [110] kCGErrorIllegalArgument: CGXSetWindowListTags: Operation on a window 0x2 not owned by caller (PID 206)

CX623 external monitor stopped working

Hello everyone,
we have a CX623 which has worked fine for years. This week the external DELL monitor stopped working. It just goes into power save mode.
The monitor and cable work if plugged into a different laptop.
A different monitor which is ok doesn't work when plugged into the CX623.
So it's 100% an issue with the laptop. Pressing Fn+F2 to change the monitor configuration doesn't resolve the issue.
The laptop does recognise the monitor and correctly names it in the display resolution settings.
Any suggestions please?

That really sounds strange....most likely it's something internal to the notebook. And honestly, there probably isn't any easy way to fix it other than replacing the motherboard.

Why did my external monitor stop working

I bought a brand new iMac on Saturday. Came home. Migrated from my MBAir (mid-2011). Plugged in my Samsung 27' TV (via Moshi HDMI to Thunderbolt converter) and it worked just great. Beautiful picture on both iMac 27 AND Samsung...Until this morning. Now, external monitor doesn't work. I've done various resets (per forum posts) NOTHING else has changed...Any ideas?

By the way...My MBA doesn't work (suddenly) either!

External monitor stopped working!!

My external monitor just stopped working today as soon as i upgraded to Mac OS 10.6.4 from 10.6.2.
When I unplug it and plug it back the screen goes blue very briefly but then nothing happens.
I tried the detect display button, I tried resetting the PRAM and nothing's working.
I really need to get that monitor to work. Help would be greatly appreciate.
Thank you

Yep, have the same problem using a 3rd party cablesson mdp-hdmi adapter. Everything worked fine until quite recently. I have tried pretty much everything to fix it but nothing seems to work. I'm almost convinced it's an OS problem, as everything works fine when I boot into my windows bootcamp partition.
Apple, please get this sorted! I'm reluctant to shell out $35 only to find that I have the exact same problem with the official adapter. Though I probably will anyway because I urgently need to get my display working again.

IMac external monitor not working after lion upgrade

Hi,
I have had an external monitor hooked up to my 09' imac for over a year now. I upgraded to Lion and ever since then it hasnt worked but one other random time when I moved and hooked everything back up. Im very tech savy, but this just doesnt make sense. Have combed google to find a solution. I have a Samsung 22in moniter and all the blue power button does is blinks at me. I am using a miniDisplay to DVI connection.
Does anyone have any suggestions other than resetting the ram?

I guess it's possible you've got some kind of hardware problem.... but not likley given it started with you installed your OS.
Here's a few things to try:
1. see if you can borrow another monitor just to be sure your monitor isn't the problem.
2. in System Prefs, and the Displays pane, click on the Detect Displays, then then the Gather Displays. If you get two diffenet display panes, that would lead me to think it's a monitor problem.
3. Lastly, disconnect your 2nd display, and restart. Then Shutdown, reconnect it, and see if that helps.
and of course..
4. make sure that all of your connections and adaptors are tight.

MBP - late 2007 - external monitor stopped working

I have a late 2007 MBP pro, 17" monitor. I have been using a 30" dell monitor (3007WFP) as an external monitor for home use. It has been working fine for 4 years. Last night the monitor stopped waking up from sleep and now only gives a blank screen even after reboots. The monitor seems ok ( it goes through the self-test routine normally), and I have tried different cables with no success.
I have tried resetting the SMC and the PRAM on the MBP but that too did not fix it.
The monitor has an orange LED light on the power button indicating the power is connected (though it is not blue which would indicate it is receiving a signal). It also recognizes that is has a DVI hook-up (or else it would repeat the self-test).
The MBP detects the external monitor (or at least seems to - it is listed as a display and allows me to choose a resolution, although obviously that does nothing since the monitor is completely black). I haven't yet been able to get another laptop or monitor to test the other components to make sure the monitor is ok.
Does anyone have any other suggestions?
Thank you

Your on the right track when you said "I haven't yet been able to get another laptop or monitor to test the other components to make sure the monitor is ok.". Also include a different cable in that scenario, if you can.
Ciao.

External monitor stops working

I'm using an external monitor hooked up with an HDMI cable. It was working fine until I upgraded to OS Maverick. I can't downgrade to my previous version of OS apparently, and no discs came with my Mac. Any suggestions? I have rebooted, restarted, unplugged everything, done and SMC restart. Using Mac Pro.

I have similar problem when I connect my MacBook Pro to my plasma HDTV. I use a mini-display to HDMI adapter and a HDMI cable. I'm trying to watch NFLIX movies on-line using my DSL modem/router that supplies the wireless connection. Watching the activity monitor, I see the incoming data (as seen on the Activity Monitor) drop to zero as soon as I plug the TV into the computer. If I disconnect the TV, incoming network data resumes, and the movie is buffered in. When I reconnect the TV, the incoming data ceases, but the movie will appear on the TV until the buffered data is exhausted. I've contacted Apple Care with no solution; they sent me to the Apple store in Albuquerque. Using my computer, adapter, and HDMI cable, Apple personnel connected my equipment to a Sharp HDTV. The NFLIX movie appeared on the TV and the incoming data did NOT stop.
No one knows why everything functioned in the store but not with my wireless setup and TV at home. I have no problem watching the movies on the MacBook Pro, but who wants to watch that tiny screen!

External Monitor Stopped Working with OSX but fine with XP

I have a viewsonic Monitor that im connecting to mbp via hdmi-dvi.
It has been working fine for the last 9-10months but has all of a sudden just stopped being detected.
If i Boot up in windows i have no problems as the monitor is detected fine, but with OSX 10.5.8 all i get is the Grey/blue screen change on the mbp when its connected to mbp or when monitor powered on or off.
There is no change to external monitor though.
I have tryed resetting the PRAM
when i go into sys pref/display, it does not detect a second monitor
I have been looking around for a few hrs now with no luck, any help would be great

Have tryed having monitor unpluged for a whole day and that didnt work, cant see any reset button on monitor.
tryed resent PRAM and PMU, tryed booting in safe mode, tryed booting from OSX disc
but didnt quite understand :
"If you see video when started up from disc, you may have corrupted software. You can use the Archive and Install feature of the Mac OS X installer to reinstall. This kind of installation gives you a fresh version of Mac OS X, but you don't lose any data from the computer as your old information is all archived."
it just booted up and asked if i wanted to install another copy of OSX.
only thing i havnt tryed from the above help is the rm command part of the out of range mac mini, and im a little cautions about that
-i can still use it fine via bootcamp, i just have to go into video settings and tell it to use dual monitors, is there anything like that on osx ? only thing i can find is the display button in sys pref and that only gives me the option to detect displays which it dont do very well.
Thanks

External monitor stopped working on Macbook Pro

I have a Macbook pro 15 with the vga adapter. I have been using it sucessfully for a month. Today it stopped working. I followed all of the suggestions online but have had no luck resolving this issue. The monitor works fine on my sony laptop but the Mac cannot see it. I have unplugged the adapter, shut down, turned on and plugged it back in as recommended. I tried a different monitor and i have simply restarted the machine with the adapter plugged in. I would greatly appreciate any suggestions.

Try doing a Parameter RAM reset - hold down command/option/p/r keys at start up and wait for three chimes before releasing the keys.

Imac - external display stopped working

Hi All,
My imac has developed a problem overnight. I usually have the imac connected to an external display via the mini-DVI connection and everything worked fine. (to DVI --> HDMI --> Pioneer Plasma).
However today the imac could not be awoken from sleep. Restarting gets to the desktop screen but then goes gray screen. After much troubleshooting, I have isolated the problem to the mini DVI port. The computer will not complete booting up if the mini dvi port is connected. Just in case it was a problem with the mini-dvi to dvi adaptor, I tested it with a mini dvi to vga adaptor. Exactly the same problem with the booting sequence (gray screen as it gets to the desktop image stage). Without the mini DVI port in use, the imac boots up fine.
Could somebody please give me some suggestions re any further troubleshooting procedures I could try to fix the problem, or does it sound like a videocard hardware problem? Thanks for any thoughts.

Welcome to Apple Support Communities
Try doing a Parameter RAM reset - hold down command/option/p/r keys at start up and wait for three chimes before releasing the keys.

External Speakers stopped working on Imac

External speakers stopped working. Verified speakers operating with Iphone. Checked that speakers plugged in correctly. Tried usual power cycling step. External speakers do not show up in sound preferences. Anyone with any advice?
Thanks,

If you unplug the speakers to the internal speakers work OK? If not try resetting the system PRAM see Resetting your Mac's PRAM and NVRAM
If they still don't work or if the internal works OK then look into the speaker plug. Do you see a red light? There is a switch inside the plug that detects the presents of a jack and sometimes it gets stuck or breaks entirely.
You could try gently using a non-conductive device (a toothpick is good) probing inside the plug to see if you can free the switch. Of course this could be harmful if done incorrectly. If the system is still under warranty you might want to take it to have it looked at.
regards

External Display Stopped Working

I've been using an external Dell 19" monitor with my beloved and faithful Macbook Pro for years. All of a sudden, I was unable to select the propert setting for the external monitor. Two days later the monitor stopped working altogether when plugged into the Mac. The Mac screen acts like the other monitor is working, but there's nothing on the external screen. The Dell monitor tries repeatedly to turn on, but the power button repeatedly changed from amber to blue while saying it's entering power save mode and never turns on. I've tried changing screen savers as recommended on another forum to no avail. I also ordered a new mini-DVI to AVG connector in the hopes that is the issue. I've confirmed that the Dell monitor still works fine by connecting it to my old PC, so that's not the issue. Any advice is appreciated. I read copy for a living and really need the larger display. Thanks!
Daniell

Welcome to Apple Support Communities
Try doing a Parameter RAM reset - hold down command/option/p/r keys at start up and wait for three chimes before releasing the keys.

Mountain Lion 1.8.2 update made my dual monitor stop working on Mac Pro mid 2012

Just done Apple's update for Mac OS X Mountain Lion to 1.8.2 and after rebooting my dual monitor stopped working.
If I go on preferences -> Displays it shows me only one of my two monitors, even if I invert the connections the 2nd monitor doesn't shows up and there seems no way to enable it again.
Any suggestion?
P.S. I already tried to set from "Best for display" to "Scaled", but after rebooting Mountain Lion 1.8.2 reset it to "Best for display"

Ok,
did some extra test here, but first of all my configuration:
Mac Pro (Mid 2012) with ATI Radeon HD 5870 1GB.
2 LCD 24" Wide-screen (1st monitor Hyundai W240D and 2nd Monitor HP w2448hc), both LCD worked perfectly until reboot after installing OS X 1.8.2
After reboot only the 1st monitor wored fine, the 2nd not even listed, so tried to invert cable connections on the 2 miniports on the ATI video card, but nothing changed, still only the 1st monitor working.
Did a second test, disconnected the 1st monitor and connected ONLY the 2nd and now the second works fine.
Tried to connect 2nd monitor on a different miniport, and i still works fine.
Updated my MacBook Pro to 1.8.2 (it as an nVidia card) and connected my 2nd monitor to it and everything works fine, both the laptop LCD and my HP LCD are working fine.
So it looks like Apple screwed up the ATI driver on the latest 1.8.2, now only ONE miniport is active.
To all users with the same Mac Pro configuration: hold to update to Mountain Lion 1.8.2 until Apple fix this driver issue.
More info are on the Console output, so will have to contact Apple on-line support to signal this bug.

External monitor only works with clam shell open

external monitor only works with clam shell open

Are you using the method in this Apple article? If you do, it should work.
Mac notebooks: How to use your computer in closed clamshell (display closed) mode with an external display

IMac External Monitor stopped working

Similar Messages

Maybe you are looking for