What should be checked first if the LCD has passed the BIST but has a video problem?

When troubleshooting a video problem on an LCD that has successfully passed the Built-In Self Test (BIST), the most logical first step is to inspect the LCD cable. The BIST indicates that the display itself is functioning at a basic level, which means the issue is likely not with the LCD panel itself but may reside in the connection or communication between the LCD and the supporting hardware, such as the graphics card or motherboard.

The LCD cable is responsible for transmitting video signals from the computer or device to the display. If this cable is damaged, improperly connected, or experiencing interference, it can lead to video problems even though the screen may still display basic signals during the BIST. By checking this cable first, you can determine if a simple re-seating or replacement can resolve the issue.

The options involving checking the power source or the battery are certainly important steps in a broader troubleshooting process, but since the display has passed the BIST, issues related to power are less likely to be the root cause of video problems. System updates can also be relevant in addressing software-related issues, but they are not the immediate concern when there is a hardware connection issue at play. Thus, inspecting the LCD cable directly addresses the probable cause of the video problem.