Thursday, November 25, 2010

How to Fix Common Problems for Laptop

LCD Video Display Problems


Here are some tips and tricks for troubleshooting and fixing laptop video problems. Video issues are very common within portable computers and with the following tips you should be able to detect and eliminate basic laptop video problems.

 

LCD screen has a faint image or is very dark

 

Look closely at the laptops LCD screen, and see if you can see a very faint image. If you can then it is possible that the Laptop's LCD lid close switch is stuck in the closed position. In this mode the backlight stays off, even with the LCD lid open. This is to conserve power when the laptop is ON with the LID closed. Check the LCD lid close switch. It is a small plastic pin located close to the back LCD hinges. Try tapping the lid switch a few times to see if you can turn on the screen backlight. If that does not help, then I would suggest to replace the FL inverter board.


LCD screen is solid white colour or garbled

 

Connect an external computer monitor to the laptop. If the external monitor display is fine, then you have a problem with the Laptop LCD screen or the LCD cable connection. If the external monitor image is the same as on the Laptop LCD, then it is likely to be a faulty integrated onboard video, this means replacing the motherboard of the Laptop. 

Randomly turns off  

This is often due to:

  • AC power adaptor sensing an overload of power drain
  • Overheating processor due to a build of internal dust (clogged fan)
  • AC power adaptor not able to sustain normal power needs (faulty power adaptor)
  • Battery overheating, due to internal battery fault, or charging levels
  • Intermittent short circuit or open connection (check condition of power leads)
On older Laptops, the most common reason is poor cooling. Try going somewhere air-conditioned and see if that helps. Inspect the areas near the internal cooling fan; see if there is a build up of dust fibres. Easy way to check this; with the unit running, feel the flow of air from the cooling outlet(s) - is the airflow very low? If yes, and the unit is at normal operation temperature, this may indicate the internal cooling system is partially clogged. 




Liquid Spills 

 I have repaired many Laptops exposed to accidental liquid spills. This is a recoverable condition in most cases. It is most important to respond to the cleaning up process as soon as possible (before corrosion or internal soakage occur)! Liquid intrusion can cause the following types of laptop damage:

  • Short circuit due to conductive nature of wet liquid (problem may clear as liquid dries)
  • Short circuit due to dried liquid residue
  • Corrosion occurs (particularly volatile with some acidic soft drinks - Coke)
  • Electronic components damaged by above short circuits
Immediately when a spill occurs, turn off the laptop, invert the laptop and leave the unit upside down (drainage) for at least 20-30 minutes. Then, remove any attached leads, remove the power unit and battery, and allow the unit to air-dry overnight.



To remove any liquid residual:

Have someone remove the keyboard assembly and perform additional cleaning. It may help to use cotton buds and distilled water to remove any contamination. Where corrosive side effects may be suspected (with coke), gently rub any suspect areas with a cotton bud dampened with CRC or WD-40. Dry the treated areas so that only a light film of the WD-40 anti-corrosive solution remains. While the keyboard is removed, use a bright light and magnifying lens to inspect areas where the liquid made contact.
























 

A typical Laptop LCD display assembly

The above simplified block diagram illustrates the basic components that are involved on a Laptop LCD video display problem.

Connector Locations 1 - 2 - 3: Video data is sent from the motherboard through to the LCD screen at connector 2. The video cable also feeds voltage to the FL inverter board at connector 3.

FL inverter PCB Locations 3 -4: This section converts the low voltage DC source (connector 3) to high voltage AC (connector 4), as required to energise the backlight bulb. If the FL inverter PCB is faulty, the LCD screen will appear as a very dim image on the Laptop display screen.

CCFL (backlight bulb): When the backlight bulb is working, you can see the image on the LCD screen. With some Laptops, the backlight bulb is a part of the LCD screen assembly and needs to be replaced with a complete LCD screen assembly. It requires a specialized Laptop repair workshop to replace the backlight bulb.

Laptop Lid close switch: This switch is a small switch (mechanical or magnetic) that is located close to the rear display hinges. Most laptops will either hibernate or operate in standby mode when the LCD is closed. This is achieved by interfacing with the Laptop's BIOS power management software. In turn this is linked to the Windows operating system. 


Laptop is slow and continually shows Internet popup's
  
The Laptop is very likely infected with spyware. Spyware is software that hides on your computer and attempts to collect information about your activity on the internet. Spyware is sometimes transferred to your computer when you download 'unknown' free software or when you link to free music Internet programs (KaZaA, Limewire, BearShare, etc). The best method to remove and further prevent spyware is to use Spybot. 


Laptop is frozen, no response to keyboard or mouse, cannot Shutdown

 

With most Laptops I have seen that this will happen from time to time! The easy method to solve this problem is:
  1. Disconnect the laptop power cord
  2. Remove the battery from the laptop
  3. Wait a short while (10 seconds)
  4. Replace the Laptop battery into the unit
  5. Reconnect the Laptop Power cord
  6. Turn the Laptop on
The Laptop will start normally and be fully operational. If you were working on a Microsoft Word or Excel document at the time of the problem, then you may find that the data has been auto-recovered for you. In this case, you will be automatically prompted to view the last document you worked on when you open the Microsoft program. 


Troubleshoot Laptop Hibernate and Standby problems

 

Power management options on laptops sometimes to cause problems. Hibernate and Standby modes are power saving modes of operations to battery powered laptops.
Hibernation is a procedure by which the working state (contents) of your work is stored to disk before the computer goes into hibernation or standby. When the Laptop is woken up, you are restored to the exact place you were before. Standby and Hibernation use a low power consumption mode, with enough power to preserve the content of such memory. This means that Laptop computer can wake up without a full restart and loss of work. 


Laptop does not wake up from Standby or Hibernation

Here are my tested suggestions:
  • Give it time - some older Laptops may take up to 30 seconds to wake up - fully
  • Some Laptops have special keys or buttons for 'Wake Up' - read the manual
  • Press and hold the Laptops power button for five seconds or more. Some Laptops are configured to Suspend or Hibernate with a press of the power button. Holding the power button for 5+ seconds will usually reset and reboot the Laptop
  • As a last resort, remove the laptop battery and the power cord, wait 30 seconds, replace the batteries and reconnect the power cord
Now that the Laptop is operational, you should research the underlying problem. Typically, such problems arise from a disagreement either between the power management features of the Laptops BIOS and Windows.

A conflict with the Laptops BIOS power management and Windows power management is the most common cause of such wake-up failure. Try different settings in the BIOS to see if that might solve the problem. Look to see if the Laptops BIOS is configured to suspend the computer, and how it compares with the value configured in Windows. In most cases let Windows control the power management.

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