Black screen of death (BlSOD) is a term that refers to a variety of error screens produced by several different operating systems (OSes). The specific meaning behind each black screen of death may vary between operating systems, though it usually signifies that the system was shut down to avoid further damage. In some cases, the screen may contain text to explain what has happened, while in others it will simply be blank. Other consumer electric devices, such as video game systems that have bricked or ceased to operate, may also exhibit a black screen of death.
Most operating systems have contained one form of black error screen or another. Early versions of Windows® could exhibit a BlSOD in connection with a disk operating system (DOS) program failing to load properly. This was less of an error screen than a symptom of the failure. The computer would typically switch to a text mode associated with DOS but fail to successfully load a program, resulting in a totally black screen that had a white, flashing cursor at the top. At that point, the only solution would typically be to restart the system.
Later versions of Windows® may also include a black screen of death, though it is typically associated with the OS failing to load. This may be the result of a missing file that has caused the computer to become stuck during the boot cycle. Solutions to these black screens of death typically involve using another computer or a bootable compact disc (CD) to replace the file, or reinstalling the OS.
Other black screens of death may be actual error screens. Operating systems based on the Linux kernel, such as Mac OS® X, will often have some type of BlSOD. These black screens of death are typically associated with a kernel panic, when the OS encounters a fatal error that it can not recover from. The screen will typically turn black and display an error message in white characters. Kernel panic and the associated black screen of death is similar to the way that Windows® operating systems may display a blue screen of death (BSOD) after encountering a fatal error.
In certain circumstances, a black screen of death may be referred to as a trap screen. These screens are typically displayed after the kernel has encountered a fatal error, and may show a variety of error codes or an information dump. Each operating system handles this type of screen differently, though there are often a number of actions the user can take. Some operating systems allow a key combination to activate a soft reboot, or a different combination to produce a kernel dump for diagnostic purposes. Other OSes may provide only the option to physically turn the machine off and back on.