The problem of no sound when using S/PDIF digital audio has been known for a long time. At the same time, probably, many users who encountered it noticed that quite often the operating system seemed to respond to playback. At least in the sound settings or in the mixer you can see the change in signal level, but nothing is heard from the connected speakers. Let's try to figure out what is the cause of what is happening and how to fix the problem.
I must say that quite often on various forums completely ambiguous solutions are offered, which in most cases do not give the desired effect, so carefully follow the instructions below.
Digital Audio S/PDIF: No sound. What is the reason?
First, let's briefly look at the possible situations in which the sounddisappears completely, and let's see why this happens. The main reasons for this phenomenon are as follows:
- wrong connection of speakers or TV (if the sound is broadcast to it);
- incorrect sound settings directly in Windows;
- disabling the main device in Windows or BIOS;
- BIOS outdated;
- disabling the audio processing service in the operating system;
- outdated or incorrectly installed audio hardware drivers;
- Priority installation of S/PDIF drivers instead of default ones.
Using the diagnostic tool
Now let's start troubleshooting. If there is no sound when using an S / PDIF digital audio device, in Windows 7 and newer operating systems, the first thing to do is to use the built-in diagnostic tool for detecting and fixing problems, which is located in the Control Panel.

Many users obviously underestimate it, believing that it usually does not eliminate the identified problems. But you don't really need it! In this case, it is much more important to identify the exact cause, and for this this tool fits perfectly (even if it cannot fix the identified problems on its own). Once the report is displayed, you will know exactly what to do next.
There is no sound for S/PDIF digital audio, but the speaker works: Steps to set playback devices
First thingyou need to check the sound settings directly in the settings of the operating system you have on your computer or laptop, using the appropriate category "Control Panel" for this. It is very common to see that only S/PDIF digital audio is shown among playback devices. There is no sound in Windows 10 because the main device is disabled or hidden.

To display all such components, right-click in the shown devices area and check two items from the additional menu. After that, turn on the disabled device (both speakers and headphones), and then set the speakers as the default device. If for S/PDIF digital audio there is no sound on the TV after connecting a PC or laptop to the TV panel, for example, via HDMI, set the audio device, the name of which usually displays the manufacturer's name, as the default device.
Note. If you still have no sound when using S/PDIF digital audio in Windows 10, expand the volume control menu in the system tray and select your TV device from there.
Actions with the Windows Audio system service
But we can assume that even after setting these options you still won't hear anything. In such a situation, it is recommended that you check the Windows Audio audio service. To do this, call the system services management section by setting the command services.msc. in the Run menu for execution.

Now findin the list of services, the desired component, double-click to go to the settings and enable the service by clicking the appropriate button. Set start type to automatic start.
Note: If the specified service is active, but there is no sound when using S/PDIF digital audio, try restarting it. First stop, reboot the system, and then turn it back on. Sometimes a restart may not be required.
What to do with integrated HD Audio devices?
If the above suggested actions did not give any effect, call the "Device Manager" and look at the state of the equipment that needs to be used. If it is disabled, activate it via the RMB menu. In the absence of drivers or problems with their functioning, it is not worth updating them using the system tools.

Better remove all present problematic components from the system, including their drivers, and then perform a full system restart. In theory, Windows itself will install new drivers. If you have the original driver disc that came with your computer or laptop, it's best to install the appropriate software from it.
General questions related to updating drivers
As for updating the sound hardware control software, do not use the system tools (it will be a waste of time anyway). It is better to give preference to, say, Driver Booster class utilities from iObit or DriverPackOnline modification solution.

If the problem persists, in the "Device Manager" find information on the identifiers of the problematic devices (VEN and DEV), as shown in the image above, then search for them either on the website of the equipment manufacturer (laptop or motherboard boards, if we are talking about integrated cards), or on resources specially designed for this, then download the required driver version, taking into account the architecture of your OS, and install it manually.
Activation of integrated cards in primary systems
Now let's see what else we can do if there is still no sound after using S/PDIF digital audio. It is possible that the primary audio device is disabled in the primary BIOS.

At the reboot stage or when the computer is turned on, enter the BIOS, then move to the advanced settings section (Advanced) or use the Onboard Devices menu, find your sound adapter there and turn it on if it is for some reason reasons turned out to be disabled by setting the Enabled parameter for it.
If the sound card is not listed at all, check the connection of the card to the motherboard (for removable devices). In the case of integrated adapters, it is better, of course, to test the entire board. However, this is not always required. The easiest way to update the BIOS is by downloading the mostfresh firmware. If you have an updated UEFI interface, you can install it directly from under Windows, and in the case of a regular BIOS, you will have to create special bootable media and / or use the tools of the primary system itself, if any.
What should I do if S/PDIF turns on by itself?
Finally, the most unpleasant situation is that sometimes the sound appears, and all devices are displayed and work correctly, but after a reboot, everything “flies” and returns to normal. At the same time, only S / PDIF audio is visible from the devices in the system. This only happens because the system itself reinstalls the S/PDIF driver and activates its use by default. In this situation, first follow the steps to install the software for the audio hardware you need, and then disable the Windows Automatic Driver Installation Toolkit.

To do this, in the section of devices and printers, selected from the "Control Panel", through the appropriate menu, deactivate all automated processes, as shown in the image above.

Also, a ban can be set in group policies (gpedit.msc), where in the device installation section, which is located in the administrative PC configuration templates, you need to activate the corresponding item. After a reboot, the driver that interferes with you will not be installed automatically and with the highest possible priority.
Note: if you do not use this device at all, you can even turn it off completely using either the sound settings or the Device Manager.