There are several possible causes and solutions for earbuds that only work on one side. Here are some of the things you can try:

1. Check the sound balance settings on your device. If the slider has moved towards one side, then the other side of the headphone won’t have an audio output. Make sure the balance slider is in the center and then you should get audio on both earbuds.

2. Clean your earbuds and charging case. Dirt and debris can accumulate in the earbuds and charging case over time, which can cause connectivity issues. Use a soft-bristled brush or a toothbrush to clean the earbuds and charging case.

3. Reconnect and unplug your earbuds. Sometimes, simply unplugging your earbuds and plugging them back in can fix connectivity issues.

4. Repair the broken wire or metal jack. If your earbuds have a broken wire or metal jack, you may need to repair them yourself or take them to a professional .

5. Test the earbuds on another device. If you're still having issues with your earbuds, try testing them on another device to see if it's a speaker issue or a connectivity issue.