What specific component provides feedback for potential video issues during testing?

The feedback for potential video issues during testing is primarily provided by the LCD cable. This component is responsible for transmitting data between the system board and the display screen. If there are any faults or issues with the LCD cable, such as disconnections or damage, it can lead to problems like a blank screen, distorted images, or complete failure of the display to function correctly. Therefore, during testing, if video issues arise, checking the LCD cable is a critical step, as it plays a direct role in the performance of the display.

In the context of the other components: the inverter board is typically involved in providing power to the backlight of the LCD screen rather than directly affecting video signal feedback. The system board contains the CPU and key components for processing, but it does not specifically provide feedback on display issues. The cooling fan is responsible for regulating temperature within the device and does not have any role related to video output or feedback. Thus, the importance of the LCD cable in diagnosing video issues makes it the relevant choice in this scenario.