Common laptop display problems
Before you consider purchasing an LCD replacement here are some of the most common laptop display failures that are not related to the LCD itself:
1. Video cable
The integral part of providing a connection between the LCD panel and the rest of the computer is its video cable. Laptop video cable is typically a short shielded bundle of tiny wires that has very fine connectors on both ends. While the side that is connected to the computer (logic board) is usually very sturdy and stress resistant, the side that connects to the LCD is known to be a common problem spot.
Problems such as a shaky and intermittent image, complete lack of image (black screen), noise and discolouration can be caused by the ajar video cable. Since this is a very easy fix, it is recommended to try reconnecting the video connector at the LCD to attempt to fix the issue. We have several video tutorials that can help with disassembly. While you have access to the back of the LCD, write down or take a picture of the LCD model number, it will help you to place an order for the exact panel you need, should you need to replace it.
2. Graphics system
The part of the laptop that is responsible for forming the image and relaying it to the display is its graphics system (equivalent of a graphics card on desktops). Its major components are the GFX chip (also called GPU), high speed memory and signalling interface modulator circuit. The GPU pre-forms frames (images) and stores them in graphic memory where each frame is picked up by the interface modulator to be sent to the LCD.
Problems such as regular visual artifacts, strange checkered patterns and intermittent blanking can be indicative of a graphic system failure. Such failures were known on scores of laptops released from 2006 to 2012. A quick internet search for your laptop model together with keyword "graphics failure" can show whether it is a common issue for your specific laptop model. Unfortunately such problems cannot be easily resolved, short of replacing the logic board. Most of the time a graphics system failure will show up on an externally connected display, therefore its best to connect a TV or a monitor to your laptop to confirm whether the graphics system has failed.
3. Back-light failure
Sometimes the screen may not light up but a faint image can be seen under the right lighting conditions or when a flashlight is pointed directly onto the LCD. Most LCD modules include own back-light source, typically a row of LEDs. Back-light is the primary draw of power in the LCD module and some circuits may require up to 2Amp @ 32Volt (64 Watts) to run the screen at full brightness. While it is very uncommon for the LEDs to be the root cause on their own, most issues with missing back-light stem from power not reaching the back-light. Power is supplied by the system through a back-light circuit that usually includes a fuse, over the video cable and onto the LCD module.
Missing back-light can sometimes be restored when the video cable is reconnected. Failures of the back-light circuit would require fine electronics repair skills on the component level to locate and replace the fuse. Very rarely the back-light failure is related to the modern LED back-lit LCDs, but it used to be a very common issue with CCFL-bulb back-lit screens on laptops prior to 2012 that would fail on the 4-5th year of ownership like a light bulb. While CCFL replacement was a common procedure on older screens, laptops manufactured after 2012 use LEDs prevalently and simply don't fail as fast, commonly lasting at least 10 years or more - much beyond the useful life of current devices.
Obvious physical damage, such as cracks, splotches of "black ink" (liquid crystal solution), regular vertical and horizontal lines require the LCD to be replaced. Water damage and depressions can also leave ugly impressions on the LCD and would require a new replacement screen in order to remedy.
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