How to cure an erratic mouse?

Question

Level 1

13 points

iMac (OS 10.11.6). Mouse is acting erratically - cursor is jumping all over screen.

I'd appreciate any suggestions.

iMac 21.5″, OS X 10.11

Posted on Sep 16, 2021 11:00 AM

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Answer 1

Top-ranking reply

Level 10

145,460 points

The following will require any USB keyboard and mouse. If you don’t have them, borrow or buy them, they are inexpensive!

Connect the USB keyboard and mouse to the computer.
Open System Preferences – Bluetooth
Un-pair the wireless keyboard and mouse.
Turn off Bluetooth
Restart the computer in Safe Mode per the directions in https://support.apple.com/en-us/HT201262
Restart the computer normally.
Open System Preferences – Bluetooth
Turn on Bluetooth
Re-Pair the wireless keyboard and mouse.
Unplug the USB keyboard and mouse and begin testing the wireless devices again.