A field technician is troubleshooting a corporate laptop whose internal display screen remains completely dark. Connecting an external monitor confirms that the operating system and GPU are functioning normally. When shining a high-intensity flashlight closely onto the laptop screen, the technician can faintly perceive active desktop windows and the mouse cursor. Upon removing the display bezel to inspect internal connections, the technician observes that no inverter board is installed within the display housing. Which of the following best explains why an inverter board is absent in this laptop display design and identifies the illumination source?
- The laptop uses an LED-backlit LCD screen, which receives low-voltage DC power directly from the motherboard via the video cable without requiring a high-voltage AC inverter.Cevap
- BThe display relies on an OLED panel that incorporates cold cathode fluorescent lamps (CCFL) driven directly by the system bus without voltage conversion.
- CThe inverter board logic has been integrated into the glass digitizer panel, requiring the touch surface assembly to be replaced whenever backlight illumination fails.
- DInverter circuitry is only necessary when outputting to external monitors, whereas internal display illumination is managed entirely by software driver firmware.
Cevap
LED-backlit LCD displays receive direct low-voltage DC power from the motherboard through the video cable, making a separate high-voltage AC inverter board unnecessary.
The faint image visible under direct light confirms that the LCD layer is working, but the backlighting is off. Modern laptops use LED backlights which operate on low-voltage DC provided directly through the main video cable from the motherboard. Therefore, no high-voltage AC inverter board is required or present in the display housing.
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