One speaker on the laptop doesn’t work. The other speaker works properly.
1. Problem with audio settings.
2. One speaker is bad.
Possible troubleshooting steps and repair solution:
First of all, check the laptop audio settings. It’s possible that the balance between left and right speakers is not set correctly and one of the speakers is simply muted.
If all audio settings are correct, most likely one of the speakers is bad.
Here’s an easy way to find out if you have a problem with settings or a bad speaker. Start playing an audio file so the sound comes from the laptop speakers (actually one speaker). Now plug the headphones and listen to the same audio. If you can hear both channels in the headphones but when you unplug them only one of the speakers starts working, it means the second speaker is bad and has to be replaced.