It sounds more like something needs to be replaced. If you've still got your mouse software CD, try deleting and reloading that. Consider replacing the mouse, entirely, all sorts of grit can get into them and cause problems.

Other than that, no guesses. I've always owned PCs, they're cheaper and less proprietary and I've run both Photo Shop and GIMP on them for years, I think my PhotoShop CD is from the late 90s.

I know I've had this problem before but no memory of how I fixed it, so I just googled "my cursor has a mind of its own," and you are not alone. Looks like there are many reasons and solutions. Good luck! Sometimes it feels like they are sentient beings to me.

Last edited Mon Sep 30, 2024, 06:20 AM - Edit history (1)

I spoke too soon. Still acting up.

Perhaps you've spilled coffee on the trackpad?

But ... unless you've replaced it, the battery in a 2012 machine is likely bad. In addition
to not holding a charge long, it can swell up and get substantially bigger.

Quick no-tools test: Put the laptop on a flat hard surface. Push on each corner (one
at a time) and see if the machine "rocks" or lies flat on the surface. If it rocks (not
just due to missing feet/pads on the bottom), you've got problems.

Old batteries will often swell. The result of it swelling include:
(1) pushing out on the bottom of the case; results in it not laying flat.
(2) pushing up ... often hitting the trackpad or other components.

Old batteries can be replaced with kits from iFixit, but it's not for those
without some serious willingness to work with tiny and breakable parts.

Ofc it could be any number of other things, but I've seen way too many
swollen batteries in my old laptops!

Good luck!

It doesn't rock at all. Actually, I had the battery replaced a couple years ago. So that isn't it. I may just have to break down and go to an Apple store. Ugh. It's basically a half day shot. What I fear is I'll have to buy a new computer.

Ah, well it is looking more like a hardware problem (failing trackpad or bad cable to it).

But since it's a pain for you to go to the Apple store, try two more things first:

1) reset parameter ram (hold down cmd-opt-p-r during boot until you hear it reboot)
2) reset the SMC. Directions written up all over the web, one copy: How to reset PRAM and SMC

Odds are not great that either of these will fix it, but they're easy to do and if either the SMC or the Parameter Ram are corrupt, it can cause all sorts of odd problems.

But haven't done the SMC yet. Maybe that'll do the trick.

Last edited Thu Oct 3, 2024, 10:15 AM - Edit history (1)

I reset the SMC and I think it did it! Ooops! It was working fine all day yesterday. But while watching a movie a bit ago, the curser started roaming around the screen. But it's not as bad. Hmmm...

Oh well, I was worried it might come back. I suspect it's time for Apple repair or a new computer ))

And the problem just sort of went away. How does that happen?

Don't worry, it'll come back when you least want it to!

Seriously ... it could be temperature/humidity related. If you go a year without it coming back, then maybe it's gremlins or dirt that's been dislodged!

On the other hand, if it comes back, but only during certain phases of the moon, then the following might be a useful read: Fail on certain Moon Phases

I'm kidding ... but the MIT bug was real

It's every couple years or so. And then, it just goes away. Not sure if anything I've done has effected it or not. Oh well...