Why My Trackpad Suddenly Right-clicks Even I Left-click?

Hey everyone,

When I turned on my MacBook Pro today, I noticed that the trackpad suddenly stopped left-clicking normally and instead only performs right clicks. I’ve already restarted it twice, but the issue remains. I tried disabling the secondary click and enabling tap-to-click, but it didn’t help. I also disabled the ctrl-click shortcut, but there was no change. Even when I connect an external mouse instead of using the trackpad, the right-click menu still keeps popping up.

Does anyone have any idea what could be causing this?

For reference, I’m running OSX Leopard on a 2009 MacBook Pro.

Hello, you can check Trackpad settings.

Apple menu > System Settings > Trackpad: Ensure that Secondary Click is either disabled or configured correctly. Tap to Click is enabled, especially if you prefer tapping instead of physically clicking.

Maybe resetting PRAM/NVRAM or SMC can help you.

Why not check for hardware damage or swelling battery? Older MacBook Pro models (like the 2009 version) are prone to trackpad issues caused by a swelling battery, which can physically interfere with the trackpad or your right-click keeping popping up.

Inspect the battery compartment for any signs of swelling. If the battery is swollen, it needs to be replaced, as this can cause both trackpad and mouse malfunctions.

What about running the First Aid in Disk Utility?

Booting in Safe Mode can help you to ensure the issue still remains.

  1. Shut down your Mac.
  2. Turn it back on and hold the Shift key immediately after hearing the startup sound.
  3. Keep holding Shift until the Apple logo appears.

Try using the trackpad or mouse in Safe Mode to see if the issue persists.

If this can’t help you, it’s sad you may reinstall macOS Leopard.