You must have some needed materials: driver and application recovery CDs and updated sound driver software.
Step 1: Check your sound card. Click "Start", than "Control Panel", and then "System" and "Hardware" and navigate to "Device Manager". Double click "Sound, Video and Game Controller". If Sound Card have been listed in this page, then you system already have sound card installed. If not, please check the enclosed information of your Lenovo IdeaPad Z500 to see if you should installed a sound card. If sound card is a must, then you should install a sound card. Note: if you have already installed sound card but not be listed in "Sound, Video and Game Controller", then go to "Other Devices" to check the list. Portable computer normally have no card sound because they have integrated sound management system.
Step 2: Take a look at all the output devices to see if they have been turned on and plugged in. The three jacks in following picture are for Microphone, input and output respectively. Check whether your output device have been put on mute or not. Check volume control setting. Go to "Start" "All Programs", "Accessories", "Entertainment", and "Volume Control" or just click speaker icon to set your volume.
Step 3: If the sound is audible but suddenly lost then you should implement system restore. Go to "Start" bottom, "All Programs" button, "Accessories" button, "System tools" and then "System Restore" and then go to System Restore Wizard.
Step 4: Sometimes you need to delete and reinstall sound driver. Click on the "Start" button, then the "Control Panel" and "System". What follows is the "Hardware", the "Device Manager" and "Sound", "Video" and "Game Controllers". Click on Sound device and then delete it. Click OK when they are a window prompt and say something like whether or not to continue the deletion. Delete all sound devices except Legacy Audio Drivers and the Audio Codec. Go to official website of your Lenovo IdeaPad Z500 and find out the updated sound driver for your sound card and download it. Then restart your Lenovo IdeaPad Z500 and reinstall the sound driver.
Now, you can have your sound out. Absolutely, sometimes sound problem may caused by certain hardware. So you can check information from your hardware supplier to see information about problems with your specific model of computer or sound card.