Sometimes windows updates can update drivers along with system files update. Drivers can be installed with the latest version and won't sync with your hardware. This may cause no sound from Lenovo laptop. This is a very common and called driver's conflict issue in windows laptops. To fix this issue you have to reinstall the driver and check if is it working or not now. (1) Right-click on the Windows logo key and go to Device Manager. (2) Toggle down to audio inputs and outputs. (3) Right-click and then Uninstall the device. (4) Your driver device would uninstall. (5) Now restart your laptop and windows will automatically install the right driver for the laptop. If still the sound is not working then update the driver. (1) Press the Windows logo and go to settings. (2) Click on Update & Security and then windows update. (3) Click on Check for Update. (4) Windows will start checking and updating the driver.