How to Repair a Faint LCD Display Moduleby Amanda Holden
Liquid-Crystal Displays, or LCDs, provide outstanding quality and unparalleled clarity in visual media. LCD displays come in many forms, from television sets to smartphones, having set a golden standard for entertainment and visual technology. These displays operate with common parts and often are simple to repair if they begin to dim.
Exercise caution when determining how and even if you should repair a faint LCD screen. Some screens lend themselves more easily to repair than others, while you should not attempt to repair others at all. You should handle old screens, such as classic cellphones or any older or legacy LCD screens, with great care. Consider asking a professional to help you with repairs, as you could inflict permanent damage to these items. Carelessness and ignorance can also permanently damage modern screens as well. If your screen remains under a warranty, don't void it by opening the device. Contact your manufacturer and have the company repair it for you.
A common culprit for a dim LCD screen lies in a malfunctioning fluorescent backlight, known as a CCFL failure. Every LCD varies in construction and size, so consult your manufacturer's documentation on how to remove any outer casing and, if necessary, the screen itself, when working with a laptop or computer monitor. Other components, such as a copper ground or an LCD controller board, may obstruct your path. Take careful note of these items and their proper locations, then gently move them out of the way until you can access the CCFL bulb. The bulb may rest in its own slot, depending on the type of screen you're working with. On either end, gently remove the rubber caps from the old bulb and place them on the new bulb. A power cable should attach at one end and may require you to solder it in place. When complete, carefully replace the CCFL and all other components within the display module, then test your LCD display module. It should return to its former brightness.
If a new bulb did not correct the problem, other hardware issues can cause the screen to dim. Take your display module apart once again and examine the power cord that attaches to the CCFL to ensure it attaches properly. It should make contact with metal or a lead on the bulb itself and should not attach to the rubber caps which will prevent or dampen the flow of electricity to the bulb. If this does not correct your problem, instead examine your LCD's power supply. When dealing with a TV or stand-alone monitor, this becomes vitally important. You may need only to replace a cord that plugs into an outlet. If more severe, an entire power board inside an LCD TV may require replacement. If your device no longer remains under warranty, refer to your manufacturer's documentation for more information.
Other components can contribute to a faint display on an LCD screen, including faulty capacitors, transistors and inverters. With proper electrical equipment, such as an voltmeter, you can measure the flow of electric current through some of these components to determine proper operation. While it is possible to replace these components if you possess adequate experience, you can also permanently damage your LCD device if you make a mistake. Consider a repair shop if you do not have professional training.
- Massachusetts Institute of Technology: Laptop LCD Turns Bloody Red (Part 0)
- Massachusetts Institute of Technology: One Thing Fixed (Part 1)
- Northeastern University: The CRT LCD Hybrid
- Jacksonville University: HP48 Repairs
- Drexel University: Troubleshooting and Repair of Consumer Electronic Equipment
- Photodisc/Digital Vision/Getty Images