Repairing - Troubleshoot Laptops

Fixing Common Laptop Problems

Repairing - Troubleshoot Laptops

Liquid Spills on Laptop

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.

Keyboard Remove Laptop

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.

Liquid Spillage - Remove Keyboard

Laptop randomly turns off

This is often due to:
  • AC power adapter sensing an overload of power drain
  • Overheating processor due to a build of internal dust (clogged fan)
  • AC power adapter not able to sustain normal power needs (faulty power adapter)
  • 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 fibers. 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.
Laptop Cooling Fan

Troubleshoot 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.

Laptop 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.

Laptop 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.

Notebook Display Assembly Diagram

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 Not Powering On Issues & Resolutions; Part 2: Video Related

Symptom: You turn on your laptop, the laptop appears to power up, but there is no display or other sign of life.

This problem affects a wide range of laptops. This is because the big graphics chipset makers –  nVidia and ATI – make chipsets for many different laptop manufacturers.

Explain: Apparently, the video chipset manufacturers switched from a lead-based solder (high melting point) to a tin-based solder (much lower melting point). This, combined with an inadequate laptop cooling solution, resulted in a chip that runs very hot – enough to melt the solder and detach the chip from the board.

All laptops have a video chip (a GPU = graphics processing unit). A video card or chip will fail mainly due to thermal breakdown. The most likely reason for this breakdown is overheating of the laptop. Overheating happens when the fan and heat-sink assembly become clogged.

Laptop Cooling Fan blockage

As shown in the photo, the dust and debris can build up. This is similar to a laundry dryer’s lint trap, except that the  laptop  does not  allow you to clean this (effectively) without a complete disassembly of the laptop.

The GPU connects to the motherboard using a BGA (ball grid array) connection; this is a connection that does not allow for physical removal of the chip without special equipment (rework machine or similar).

Video GPU uses a BGA (ball grid array) connection

Thermal Over-Exposure is what creates failures in the BGA connection grid of the GPU (video chip). The heat combined with some GPUs using incorrect solder; will break down the solder ball contact  connection over time and over prolonged  exposure to overheating conditions (clogged fan/heat-sink).

The BGA can be gently heat-flowed intact - but I do not recommend this is done as a hobby attempt - other than 'desperation' as the technique is complex.

Possible "simple" short term fix: Place the Laptop in a warm bed with the electric blanket switched to max heat for a few hours. This usually is enough to boot (once) for a short period.

Summary: Over time, as the laptop is switched on and off over and over again, and as the chipset repeatedly goes from cold to very hot, the solder under the chip begins to fracture, and eventually the chip partially separates from the motherboard, resulting in minor malfunctions and finally failure of the video.

Laptop is slow and continually shows Internet pop-ups

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. Please read my Spyware Software Help Page.

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

Solution 1 (Windows only):

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.

Sometimes your computer may become completely unresponsive, or frozen. When this happens, you won't be able to click anywhere on the screen, open or close applications, or access shut-down options.

Solution 2 (Windows only):

Restart Windows Explorer. To do this, press and hold Ctrl+Alt+Delete on your keyboard to open the Task Manager.

Next, locate and select Windows Explorer from the Processes tab and click Restart.

You may need to click More Details at the bottom of the window to see the Processes tab (see image below).

Windows Task Manager - Processes

Solution 3 (Mac only):

Restart Finder. To do this, press and hold Command+Option+Esc on your keyboard to open the Force Quit Applications dialog box.

Next, locate and select Finder, then click Relaunch.

Command+Option+Esc on your keyboard to open the Force Quit Applications

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.

Laptop Won't Power On

Notes: Before Disassembling Laptop always unplug power and remove the battery.

The flowchart and text below were specifically designed to help you troubleshoot laptop hardware problems.

The diamond symbols (below) are linked to text that explains each possible decision point.

Laptop Trouble Shoot Flow Chart

Most laptops have a series of LED's (lights) on the front (or back) edge that show a basic status report.

Normally, there are separate LEDs that will light when the when the laptop power cord is plugged in, when the battery is charging, and when the laptop is powered on.

In addition, older Laptops have LEDs for hard drive and wireless activity.

At this diagnostic step, we are interested in the LED that shows that external power is connected or that the battery is charging. These are the only LEDs that should be lit when the laptop isn't turned on but is plugged into a live AC adapter.

Listen: When one or more status LEDs on the laptop are lit, it may be that the basic power circuitry is functioning, but the boot process is being aborted before it even starts. If you can hear the hard drive spinning up or the CPU fan come on and stay on, or if the hard drive activity LED blinks regularly, there is a good chance that the problem is isolated to the video display subsystem. A simple and  quick test is to attach an external monitor, though you may have to use a key combination (normally the master Fn (Function) key along with one of the other keys along the top of the keyboard) to have the laptop use the external video port.

Does the Laptop power up with the battery removed? If the laptop does power up without the battery and the manufacturer or documentation confirms that battery-free operation is acceptable, you can treat the Laptop as a portable desktop. Otherwise, you can purchase a replacement battery, but the problem may turn out to be with the internal circuitry.