When it comes to reliability and credibility, Mac has an edge over other computers. Mac users do not often face much trouble from their devices, but when they do, they face some weird ones. For instance, some Mac users have reported that Mac cannot find any input or output audio devices.

For some users, the output doesn’t show up, and they end up with a muted / silent Mac and an error message in System Preferences stating, “No output devices found. This issue is not new, but strangely it hasn’t been addressed by Apple properly. However, there are a few quick troubleshooting techniques that can provide a solution. Have a look at them.

Repair Disk Permissions and Reboot:

Before opting for any other troubleshooting technique, it is highly recommended that the users should go for repair disk permission and reboot option. This technique is well and truly tested in solving various Mac issues and therefore, it is worth a shot for no input no output issue as well.

Software Update:

Not updating the software for any reason could cost you dearly. Users who do not update their Apple devices usually end up in some sort of trouble. If you are facing this no input no output error then you should instantly head to App Store and check for available updates for your Mac. Install any available updates, then check for updates again as some updates appear only after the previous updates are done. Once done, restart your device and see if the issue has been addressed or not.

Adjusting Sound Preference:

Another thing you can try to fix this issue is to adjust the sound preference on the Mac. To do that, open the system preference and hit the option Sound. Next, choose the Output tab followed by selecting the internal speaker as the default audio output device. Adjust the volume and make sure the mute is unchecked. Now see if the issue has been addressed or not.

Reset Core audio service & Restart:

Core Audio service (CoreAudio) is Apple’s low-level API which deals with sound on the Mac. There is a slim chance that things could have gone wrong with core audio service and thus prompting this issue. If your core audio service is stuck then you may have to restart the CoreAudio to address the issue. All you need to do is to open the Terminal via the Utilities (System Preferences) route and then type in the command sudo killall CoreAudio followed by pressing the enter key. This will restart the CoreAudio and may well address the no input no output error as well.

Try resetting SMC and PRAM:

The system management controller (SMC) is a chip in your Intel-based Mac, which plays significant roles in controlling integral things of the Mac. They are responsible for thermal and power management, keyboards and other peripherals like the audio board, battery charging etc. So, if you are facing the no input no output issue then resetting the SMC could be defining in addressing this issue.

Likewise, Resetting PRAM will reset all of the system buses on your computer, USB, audio port, FireWire, Ethernet etc. you can consider it a detailed troubleshoot and therefore it has a much better chance of addressing the issue as compared to the other techniques. Resetting SMC and PRAM is a tad complex and therefore you should take someone’ help before opting for this option.

Reinstall OS X:

The last thing you can do for addressing this issue is to reinstall OS X. It will not lose any of your files or document they will remain as is. Restart your computer and hold down Cmd+R together until you see grey Apple Logo. Make sure the Mac is connected to the internet and then choose the option reinstall OS X and hit continue. You will need to follow the on-screen instructions until the process is complete. Many people have addressed the no input no output issue through this technique and therefore the probability of success with this method is quite high.

Conclusively, if none of these techniques helps then it could be a hardware issue and it is recommended that users should seek advice from a reputable source for addressing the hardware related issues.