Bug: Dotted line dragging along with the mouse pointer

Hi All --

I'm late to the party, but I have a super quick fix for this issue -- at least as described by most and illustrated in pkwong@sd38's screenshot.

Simply make sure the laptop is NOT asleep, and then plug the projector back in via the thunderbolt to vga adapter, and voilà! Problem gone. The project doesn't even have to be on.

Hope this can still help some folks. BTW -- my mac is late 2012 (OS 10.9.5), so it's a persistent issue, not just with mid-2010s.

Jchlbk

Hey there!

It sounds like you are seeing some graphical anomolies when using an external monitor. I would use these troubleshooting steps from the following article to help resolve the issue named:

Apple computers: Troubleshooting issues with video on internal or external displays

http://support.apple.com/kb/ht1573

1. If you're using an Apple notebook, confirm the AC power cable or adapter is securely connected to the computer and the cable providing power to the display is also secure. It is always good to have your notebook connected to AC power when an external display is in use.
2. Confirm display adapters are fully seated in their respective connections and that they are supported models and for the computer and display. Refer to these articles to assist you with adapter compatibility and further configuration information:
   • Monitor and Display Adapter Table
   • About Mini DisplayPort to HDMI adapters
   • Apple Mini DisplayPort adapters: Frequently asked questions (FAQ)
   • Thunderbolt ports and displays: Frequently asked questions (FAQ)
3. Remove all display cable extenders, KVM switches, or other like devices and retest to determine if the issue is resolved.
4. Try unplugging the video adapter or cable and then plug it back in.
5. If more than one video adapter is in use (or "daisy-chained"), troubleshoot by using only one adapter.

   Example: A mini DisplayPort to DVI adapter connected to a DVI to HDMI adapter is an unsupported configuration because there is a series of adapters in use.

6. If available, try using a different display and or adapter (or use a different connector by using DVI instead of VGA, for instance).

Reset the system
You can reset the Mac's parameter RAM and SMC.Reset the resolutionStart by resetting the Mac's parameter RAM. If the display does not come up, was previously set to an unsupported resolution, and still results in no video:

1. Start up in Safe Mode.
2. From the Apple () menu, choose System Preferences.
3. Choose Displaysfrom the View menu to open the preferences pane.
4. Select any resolution and refresh rate that your display supports.
5. Restart your computer.

Thank you for using Apple Support Communities.

Take care,

Sterling

We are having this same issue across multiple sites. They seem to be only affecting the Macbook Pro models (2010). A restart fixes it, but it recurs randomly. I called Apple and they feel like it has to do with our image. However, I have yet to confirm this. PRAM reset and SMC reset could fix it but the problem recurs. Any concrete answers or experiences appreciated!

We're having the same problem with a pair of MacBook Pro laptops. The common denominator, after chasing this for months, seems to be Mavericks and connecting to and/or disconnecting from a projector via the VGA port. (Neither machine experienced this issue when running 10.8)

I make a Genius Bar appointment and brought one of the MacBooks to the Apple Store. They ran all their diagnostics but found nothing wrong with the computer. They felt I should reload Mavericks. (I was considering it until a second one turned up with the same problem.)

This thread on the Mac Forums site seems to be essentially the same issue. Lots of people giving the standard 'reset PRAM' sort of dogma (which don't help, BTW) but no real answers:

http://www.mac-forums.com/forums/os-x-operating-system/305926-strange-shape-arou nd-mouse-pointer.html

I would like to see a solution before I push any more users to Mavericks,

- Christopher

We bought 30 2012 Macbook Pros for our teachers and almost every laptop has this same issue! I have been scouring the net looking for others who are experiencing it. As you all have said, it happens randomly when disconnecting from a projector (we have them in all our classrooms with Smartboards). It is a real pain. Knowing someone took it into the genius bar with no clear answer at least tells me I don't need to take one in for it to be looked at. Wish I had an answer as well....

Is there a way to expedite this to QA? I work for LAUSD, seems to be a common issue on the teacher's laptops. They're used with projectors and doc cameras as well.

Same problem with our district laptops-- running Mavericks on MacBook Pro! We also are all connected to projectors and document cameras. Sometimes it gets so bad you can't even see where the pointer is pointing to be able to restart. Very frustrating!

Hi, I've been having this problem with my 2012 MacBook Pro, even on OS Yosemite, and I plug it to projectors every day for my classes. Then I got this advice from a friend and it seems to work: (1) switch off the projector while the laptop is still plugged in; (2) ONCE it has been switched off, then close the laptop; (3) then unplug the VGA cable (4) open the laptop again. It has worked for me several times already. He also told me to then click on the "search screen" option, but I have not found this option anywhere. Hope this helps.

Hi again,

This seems to work better now for me: (1) switch off the projector while the laptop is still plugged in; (2) ONCE the projector has been switched off, then unplug the VGA conector from the laptop; (3) then go to System Preferences - Screens - click on "Recommended for this screen". Good luck!

I am having the same exact issue. Hadn't considered the connection with using a projector, but I was using a VGA projector right before I noticed it this afternoon.

I have the same problem and know what triggers it and so how to avoid it.

It happens when the external monitor is disconnected while the mac screen is on sleep mode( say after a few minutes)

try to disconnect the external display while the screen is still active. For me it works, and the mouse pointer remains well.

I have found that this problem occurs specifically when visiting a flash-based site: scratch.mit.edu is the biggest problem. It never occurs at other times and I am connecting to my classroom projector multiple times a day. Anyone have thoughts about this? A fix would be nice!

I am the IT in a school district and after a lot of testing, this problem has to be a software/driver issue. I am able to duplicate this problem when the following criteria are met:

- Macbook Pro (13-Inch Mid-2012)

- 10.9.x or 10.10.x (Factory untouched or/and Imaged by Casper)

- Projector capable of 1920x1080 (Acer P7500 used in the test)

- Apple Mini DisplayPort to VGA adapter

This will happen when:

1) Macbook Pro is connected to a projector via a Mini DisplayPort to VGA adapter

2) The resolution of the Macbook Pro display is changed to match the projector

3) Unit MUST put into sleep

4) Mini DisplayPort to VGA adapter is removed while Macbook Pro is sleeping (LED pulsing)

5) Turn on Macbook Pro

6) Notice Macbook Pro display flashes as it switches resolution and the mouse pointer remains the same size like the 1920x1080 resolution; also notice the weird graphic on the mouse pointer

7) When the mouse pointer is clicked on a field that you can type, a double pointers is shown.

If you try to do this with a DVI or HDMI adapter, this will NOT happen. This only works on VGA.

I am very positive that this has to do with the video drivers on the 13-Inch Mid 2012. I've tested this on a Macbook Air and Macbook Mid 2010, I am unable to duplicate the problem.

Addition: When this happen, I noticed the Macbook Pro display color is off, I have my display calibrated with a colorimeter so I think the machine is still using the profile from the projector even when it is disconnected.

Temp solution: Only unplug the DisplayPort adapter when the machine is NOT in sleep or reset SMC+PRAM.

This has to do with the graphics drivers in Mac OS because when I try to take a screenshot, I cannot get it to capture the mouse pointer.

Now I've provided with consistent results, I hope Apple could look into this problem.

I'm the Assistant Director of Technology in a Catholic high school, and our department purchased 75 new MacBook Pros (13-inch, Mid 2012) to replace our unibody MacBooks that were being used by our faculty. I've been approached by several members of our faculty stating they see cursor distortion after disconnecting from their projectors. The photos in this thread match exactly what I see when a teacher brings their laptop to me. I agree with everyone in this thread that it seems to happen when the computer and/or display is asleep and the teacher disconnects the video adapter from the computer. All the software is up to date (OS X 10.10.5 as of this post). Ive advised our faculty to ensure their computer is not sleeping when they connect and disconnect their adapters. Until then, I'm hoping Apple sees this as a real issue and pushes out some type of update to fix it.

Hi cross29fire and all,

I have the same problem. It only shows up on MacBooks which have been used with projectors. We are a Charter School replacing white Unibody MacBooks which are five and more years old. We replaced them in early August 2015, with 135 new MacBook Pro's, i5, 4GB RAM. Those used by the Teachers are the only ones having the cursor problem. We have both "true" Apple VGA to mini-displayport and Tripp-lite "compatible" VGA adapters. The issue appears with both adapters. Student units do not have any cursor issues, as they have never had an external monitor connected. We have sent two units back to Apple (via AppleCare) for servicing, and in both cases they replaced the motherboards. One unit with a new motherboard has the problem again.

Apple, please address and fix this problem!