Your laptop screen was working properly yesterday, but now the display doesn’t show anything. When booting up the laptop, you notice that the LCD display backlight isn’t turning on at all and you can see a faint image appearing on the LCD panel. Connectivity to an external monitor works normally. What is the most likely problem?
A) The LCD inverter is bad
B) The LCD panel is faulty
C) The LCD panel open/close switch is faulty
D) The operating system software is automatically selecting the external monitor instead of the internal LCD display
The answer: A) The LCD inverter is bad
The LCD inverter powers the backlight that sits behind the LCD panel. Without the backlight, it’s almost impossible to see the liquid pixels on the LCD screen. If an LCD backlight is working sporadically or not at all, you probably have a bad inverter. Fortunately, inverters are relatively inexpensive and easy to fix.
The incorrect answers:
B) The LCD panel is faulty
If the LCD panel wasn’t working, you wouldn’t be able to make out any images on the display or the images would be garbled and unrecognizable.
C) The LCD panel open/close switch is faulty
A switch inside the laptop can detect if the display is open or closed. If the LCD display is open, the laptop will power the LCD panel and the backlight. Since the LCD is displaying information on the screen, we can logically conclude that the switch is operating normally.
D) The operating system software is automatically selecting the external monitor instead of the internal LCD display.
If there’s information displayed on the LCD screen, then we should be able to see it clearly and tell that the backlight is working properly.
 | Want to know more? Watch “Diagnosing and Troubleshooting Laptops and Portable Devices.”When your portable device starts having problems, where do you start the troubleshooting process. Unlike traditional desktop personal computers, laptops and portable devices have additional steps for diagnosing troubles. In this video module, we’ll troubleshoot the boot process, video settings, stylus and digitizer issues, keypad problems, and antenna wires. |