Monday, 17 October 2011

The Flickering LCD Screen on a Laptop

The Flickering LCD Screen on a Laptop

LCD screens on laptops can be a very finicky animal. One of the most common problems is a flickering screen. This can be seen when you move the screen back and forth and it goes in and out. Though, this problem can be tolerated, it is best to resolve it as soon as possible. If it is not fixed soon, then the LCD screen can go out permanently. There are numerous things to consider when try to troubleshoot the cause of this problem. Here are most of the causes:
  • Loose Cable

The loose end of the cable could be behind the LCD screen or loose from the connector on the motherboard. The more common of the two is the connection behind the LCD, which is also much easier to access. This only involves unscrewing and removing the facemask and unscrewing it from the brackets. You will then be able to reseat (Remove and reconnect) the connector from behind the screen. If this does not resolve the issue, then you will have to take the laptop partially or completely apart to get to the connector on the motherboard. 
  • Bad Cable
Any fraying or tearing of LCD cable can also result in a flickering screen. Check to see if there is any visible fraying or tearing of the cable close to the hinges. In most cases, loose or badly manufactured LCD hinges are the cause of the torn cable. You might have to tighten or replace the hinges, in addition to replacing the cable to resolve this issue. LCD cables can also tear inside the protecting cover. About 70% of a flickering screen's causes will be a loose or bad cable, so these are the first two troubleshooting steps you should try. Always try a new cable before attempting another diagnosis. 
  • Bad or Loose Connector on the LCD
This usually happens from normal wear and tear. Although, the least common cause, it can still happen. The suggested method of repairing a bad connector is to replace the entire screen. Soldering a new connector on there can have very bad consequences, even if you are very good at soldering. The LCD is very heat sensitive. Then, there is the problem of finding a connector from an exact same manufacturer and model of laptop. If you happen to have one, there is no guarantee that connector is good. The connector is not sold separately. So, the only way of finding a known good connector, is if it is from a known good LCD screen. Then, you might as well just replace the whole screen. 
  • Bad or Loose Connector on the Motherboard
Opening and closing a laptop can also cause strain on the motherboard LCD connector. Slowly, the heat with the constant pulling will eventually loosen the connector. Re-soldering in this case is a valid option. Even using a heat gun and pressing down on the connector can reseat it back in place. Of course, if that does not work, then replacing the motherboard is the only option left. 
  • Bad Video Chip or Card
The same thing that happens to motherboard LCD connector can also happen to the video chip. The intense heat can cause the connection to loosen. The same fix can be used here. Use a heat gun to heat the connector while pressing down firmly on the chip. A loose video card can simply be reseated. Just remove and insert the card back into the slot. Make sure the heat sink is firmly attached before trying the video again.
This is not the end all of flickering LCD screen causes, but these will get you through about 90% of them. Always check the cable first. The other causes are manufacturer specific and more research needs to be done to determine the cause. Hopefully, this will help you find out the causes and you will be able to make an informed decision on which technician to choose to take the laptop to.

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