Cursor stuck in a corner of the screen

[DrNo]

Hi, I have an iMac (Retina 5K, 27-inch, Late 2015) running El Capitan and I've been experiencing this already three times: the cursor gets stuck in the upper left corner of the screen and the only thing I could do was a hard reboot by pressing the off button.

How can I unstuck the cursor without rebooting? How can I fix this so it won't happen again?

Using another mouse doesn't help: right now connected with the iMac are an Apple Magic mouse, a USB Apple keyboard, and a USB IBM keyboard with trackpad and pointing stick, that I use just for the trackpad. None of the three methods (mouse, trackpad, stick) is able to move the cursor. The IBM keyboard works flawlessly on another iMac.

 

[BrianBaughn]

The IBM keyboard works flawlessly on another iMac.

With the same input devices attached? Same OS version?

 

[kschendel]

Is the mouse connected through the keyboard, or is it an independent connection? Next time it gets stuck, try disconnecting the keyboard, connecting only the mouse, and see if you can move the cursor. Also, when it gets stuck, can you tell if the computer is still doing stuff, or is it completely frozen? e.g. does the clock keep time, etc.

 

[Fishrrman]

The normal "appearance point" for the cursor at bootup time is the upper-left-hand corner.

Sounds like you don't have any "communication" between your pointing device and the Mac.

I suggest you try a WIRED USB mouse. A non-Apple one might be best.

 

[DrNo]

With the same input devices attached? Same OS version?

Yes (only difference is that on the other iMac I have a USB mouse instead of a Bluetooth mouse).
[doublepost=1486053835][/doublepost]

The normal "appearance point" for the cursor at bootup time is the upper-left-hand corner.

Sounds like you don't have any "communication" between your pointing device and the Mac.

I suggest you try a WIRED USB mouse. A non-Apple one might be best.

I do have communication: I can move the cursor slightly away from the corner with either the magic mouse, the trackpad, or the pointing stick, but the cursor moves back to the upper left corner within fractions of a second. It feels like it's strongly attracted to the corner, I don't know if I'm explaining myself well.
[doublepost=1486054062][/doublepost]

Is the mouse connected through the keyboard, or is it an independent connection? Next time it gets stuck, try disconnecting the keyboard, connecting only the mouse, and see if you can move the cursor. Also, when it gets stuck, can you tell if the computer is still doing stuff, or is it completely frozen? e.g. does the clock keep time, etc.

It's an independent Bluetooth connection. The two keyboards (I also have an Apple keyboard) are connected via two separate USB ports. The computer is still working fine, I can switch between windows with command tab, type, etc.
but I cannot use the mouse. I contacted Apple support and their answer was: 1. Update to Sierra (seriously????). 2. Reestablish the SMC. I did the latter, I don't know if it solved the problem (on previous occasions the problem also was temporarily solved by restarting the computer).

 

[curmudgeonette]

I do have communication: I can move the cursor slightly away from the corner with either the magic mouse, the trackpad, or the pointing stick, but the cursor moves back to the upper left corner within fractions of a second. It feels like it's strongly attracted to the corner, I don't know if I'm explaining myself well.

It sounds like one of your input devices is stuck generating mouse movement toward the top left. When the problem happens, do as @kschendel suggests to try figure out which is the problem device.

Next time it gets stuck, try disconnecting the keyboard, connecting only the mouse, and see if you can move the cursor.

 

[DrNo]

It sounds like one of your input devices is stuck generating mouse movement toward the top left. When the problem happens, do as @kschendel suggests to try figure out which is the problem device.

I forgot to mention that I had already tried disconnecting one device at a time last time it happened, and it didn't solve the problem.

 

[BrianBaughn]

I forgot to mention that I had already tried disconnecting one device at a time last time it happened, and it didn't solve the problem.

It's likely a type of "crash" and you can't "uncrash" once it's happened. Checking the console to see what happened might help.

Yes (only difference is that on the other iMac I have a USB mouse instead of a Bluetooth mouse).

That would actually be a "No" answer.

 

[kschendel]

I forgot to mention that I had already tried disconnecting one device at a time last time it happened, and it didn't solve the problem.

This might be what you did, but just in case ... I am suggesting that you disconnect ALL of them, including any dongles for wireless input devices. Take any bluetooth devices out of the room and sufficiently far away that they can't be talking to the computer. Then, hook up ONE mouse, preferably a dumb USB wired mouse that checks out OK on another machine (or, spend $10 for a new one at an office supply store). See if the cursor moves. If it does, you have an input device problem of some kind. If it doesn't, you probably have an internal failure of some sort. If the clock doesn't advance when it's in a stuck state, that also points to an internal fault.

edited to add: if you have Bluetooth enabled, and it sounds like you do, I'd also look around for any bluetooth capable devices that might possibly be going nuts. Do you have an old mouse in a drawer or something? Wireless input devices are nice, except when they start causing problems, and you don't always realize when one is turned on and sending stuff that you maybe didn't expect.

 

[hfg]

Do a PRAM reset, if you haven't already tried that.

https://support.apple.com/en-us/HT204063