Sound automatically changing to maximum volume when headphones and charger are plugged in

awang2342 wrote:

I have a Macbook Pro 13" 2017 running Mojave 10.14.5. For some reason, if I keep my charger plugged into the laptop along with the headphones, the sound automatically goes to maximum. When I put it down, it goes back to maximum right away. I tried doing the option+cmd+p+r sound reset, but that seemed to do nothing. If either my charger or headphones is not plugged in, the problem does not persist. I have tried restarting the computer several times. The problem happens regardless of what apps are open. I also tried to stop the coreaudiod and let it restart.

Any help would be appreciated.

To trouble shoot further you can:

Try a SafeBoot https://support.apple.com/en-us/HT201262

Takes noticeable longer to get to the login screen, does a 5-15 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc.

This test will tell you if third party interference; extensions etc are not loaded in safe boot mode.

Test issue in another user (or guest user) account  https://support.apple.com/en-us/HT204443

This will tell you if it a universal issue or isolated to your user/admin account.