Mouse cursor moves only on part of the screen

jr309 wrote:

Hi,

I have a Mac Mini MGEQ2*/A running High Sierra. A Magic Mouse 2 and a Magic Keyboard. This setup is attached to both a Dell monitor and an NEC projector as part of a classroom setup. We alternate between having the displays extended or mirrored from time to time depending on what is being shown in the class and if we need to record things from the screen. Recently, we've noticed that occasionally the mouse cursor will not past a certain portion of the screen, usually the right hand corner of one of the displays, if not both displays. The last time the problem happened, the screens were extended. The last time it happened, I plugged in another non-Apple mouse to see if that would fix the issue, but it persisted. I had to restart the computer to get the mouse working again.

Addressing issues with Mouse scaling—

Try resetting NVRAM/PRAM http://support.apple.com/kb/ht1379

1. Shut down the computer.

2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.

3. Press and hold the Command-Option-P-R keys.

4. Turn on the computer.

5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.

6. Release the keys.

<edited by leroydouglas>

Did you look in System Preferences->Displays->Arrangement?

It will let you set up your displays’ relative positions. It could be that the display you set on the right hand side is also shifted somewhat above or below the other display. In that case there may be no place to go right if you are, say at the bottom right corner of your left display; but move your cursor up a bit and then you can move to the right and reach the other display.

Here is a picture from System Preferences ilustrating what I mean: