Why do I have to unplug the computer speaker cable from the computer case and plug it in again every time I turn on the computer to get sound?

There are 2 most likely scenarios for this problem, 1 is the sound card problem, and 1 is the affected device problem. Please check your sound card for poor contact, such as too much dust. Check whether your sound card driver package is complete, the computer loads a lot of content when the computer is just turned on, probably because the system occupies a large, and the driver has not been able to run in a timely manner, the initialization is not complete, so after the power on and wait a while before the sound. Check your connection plug whether there is poor contact, a connecting cable inserted for too long, it will be deformed, resulting in the next recognition failed to detect and recognize, so there is no sound, you can find a headset plugged into the experiment, whether it is the connection casting problems. You can also test whether it is a sound hardware problems, some audio to have current before sound playback, some of the complex audio signal processing can not, some in the ability to play more continuous audio signal! The simplest way is to touch to change a sound card, to touch to change a sound, it is good!