Headphones not working when plugged in can often be attributed to incorrect settings, faulty ports, or cable problems. First, make sure your headphones are fully inserted into the port, as partial connections can cause audio issues. Then, check your device’s audio settings to confirm that the headphones are selected as the output device. You may need to adjust the volume settings to ensure they’re not muted or too low. Testing your headphones with another device can help determine if they’re the issue. If they work on a different device, the problem might be with your computer or phone port. Sometimes, lint or dust can clog the headphone jack, so carefully cleaning it out with compressed air can improve connection quality. Updating or reinstalling audio drivers can also resolve compatibility issues on computers. If none of these solutions work, the headphones themselves may need repair or replacement.