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Comprehensive list of common laptop faults

Due to the particularity of its structure, the complexity of laptop repairs is determined. But a laptop is a type of computer after all, and its maintenance principles are basically the same as those of ordinary desktop computers. If you are a laptop user and are interested in its repair knowledge, then you can refer to this article. Here are some analysis and processing procedures for solving laptop faults, which may help you.

Common faults of laptops-not lighting up when booting-hardware judgment

---Laptop motherboard BIOS failure will cause not lighting up when booting

---Laptop computers The CPU fails and the laptop LCD screen becomes unresponsive, which is also the reason why the laptop does not light up when it is turned on.

---A failure in the signal output port of a notebook computer may cause the computer to not light up when it is turned on

---A failure in the graphics card control chip on the motherboard of a notebook computer may cause the computer to not light up when it is turned on

---A laptop graphics card failure may cause the computer to not light up when it boots up

---A laptop memory failure may cause the computer to not light up when it boots up

The laptop battery cannot be charged - hardware failure Judgment

---A failure of the laptop power adapter will cause the battery to be unable to charge

---A failure of the laptop battery will cause the battery to be unable to charge. < /p>

The notebook does not recognize the peripherals - Hardware fault diagnosis

---Faulty laptop-related peripheral hardware will cause the notebook to not recognize the peripherals

--- A faulty laptop BIOS and incorrect settings may cause the laptop not to recognize peripherals.

---Faulty laptop motherboard peripheral-related interfaces will cause the laptop not to recognize the peripherals

---Faulty laptop motherboard will also cause the laptop not to recognize the peripherals. At the same time the laptop won't turn on.

A failure of the notebook motherboard will cause the following symptoms

---The notebook computer will not recognize the notebook hard drive after it is turned on.

---The notebook computer does not recognize the notebook optical drive after booting.

---The laptop battery is not charging.

－－－The laptop shuts down regularly or irregularly.

---The laptop keyboard is not working.

---The laptop sometimes loses power when turned on.

——Laptop computer crashes regularly

The above fault phenomena are all related to the laptop motherboard

The fault phenomenon caused by the laptop power adapter

--The laptop does not light up when it is turned on.

---The laptop freezes intermittently.

——The laptop power adapter is hot.

--Laptop computer's optical drive may easily crash or lose power when reading DVDs.

--Laptop computers are prone to crashes or power outages when running large programs.

The above fault phenomena are all related to the notebook power adapter

Introduction to the notebook optical drive

The mechanical drive part of the notebook optical drive.

Laptop optical drive-laser head assembly.

Laptop optical drive failures mainly come from these two parts (laptop optical drive).

1. The driving mechanical part is mainly composed of three small motors: the disc loading mechanism is composed of motors that control the entry and exit of the box compartment (loading), and mainly completes the loading and unloading of the disc. Box (unloading); the laser head feeding mechanism is driven by the feed motor to complete the smooth movement of the laser head from inside to outside or from outside to inside along the radius direction of the optical disc to quickly read the optical disc data; the spindle rotation mechanism is mainly driven by the spindle motor. The rotation of the optical disc generally adopts the DD control method, that is, the rotating axis of the optical disc is the rotating axis of the spindle motor.

2. Laser head assembly is the most important and fragile component of various optical drives. The main types include single-beam laser heads, three (multiple)-beam laser heads, holographic laser heads, etc. It is actually a whole. An ordinary single-beam laser head is mainly composed of semiconductor laser, semi-transparent prism/collimation lens, photosensitive detector and actuator.

Analysis of common faults of notebook optical drives

The most common failure of a notebook optical drive is mechanical failure, followed by circuit failure, and circuit failures are caused by improper user adjustment much more often than component damage, so when disassembling or maintaining the optical drive Do not adjust the various potentiometers inside the laptop optical drive casually during installation

There are three main types of common laptop optical drive faults: operational faults, accidental faults and inevitable faults.

1. Operational failure, such as driver error or incorrect installation, causing the notebook optical drive to not be found in Windows or DOS; notebook optical drive connection cable or jumper errors making the notebook optical drive unusable; CD cable not connected properly. Listening to CDs; the notebook optical drive is not placed correctly on the tray, causing the optical drive to not read the disc; the optical disc is deformed or dirty, causing unclear images or pauses or severe mosaic; improper disassembly causes various connections inside the optical drive to break or loosen, causing malfunctions wait.

2. Accidental failure: Random failure of notebook optical drive, such as early failure or sudden damage of internal integrated circuits, capacitors, resistors, transistors and other components, or sudden damage of some frequently moving mechanical parts. Although this type of fault is rare, it must be repaired and replaced to eliminate the fault, so accidental faults are also called "real" faults.

3. Inevitable failures: Failures that will inevitably occur in a notebook optical drive after being used for a period of time mainly include: aging of the laser diode, longer disk reading time or even failure to read the disk; dirty optical lens in the laser head assembly/performance Deterioration, etc., causing audio/video distortion or crash; mechanical transmission mechanism causes failure due to wear, deformation, and looseness.

It should be noted that the repair rate of inevitable failures not only depends on the quality of the product, but also depends on the user's manual operation and maintenance, the frequency of use and the environment.

Judgement of common faults

1. If the optical drive cannot be detected when the computer is turned on, first check whether the optical drive jumper is correctly jumped; then check whether the optical drive IDE interface is poorly connected. If not, you can Plug it back in and tighten it; finally, the data cable may be damaged

2. The failure of entering and exiting the box is manifested as being unable to enter or exit the box or being unsmooth. The possible reasons and troubleshooting methods are: entering and exiting the box compartment The motor pins are in poor contact or the motor is burned out - they can be re-inserted or replaced; the transmission belt (rubber ring) in the mechanical structure of the inlet and outlet box is loose and slipping

3. Laser head failure The fault phenomenon is manifested as picking the disk (some The disk can be read, but some disks cannot be read) or the disk reading ability is poor. If the optical drive has been used for a long time or is frequently used to watch VCD or listen to CDs, the objective lens of the laser head may become dirty or aged.

★We warn you not to use some low-priced and inferior optical head cleaning disks on the market, because the bristles of these disks are too hard, which will scratch the objective lens, and may also cause static electricity hazards and shorten the optical drive. service life.

4. The fault of the laser signal path refers to the connection line between the laser head and the circuit board, which is the channel for information exchange between the laser head and other circuits. There are many faults here. .

5. Spindle signal path failure. Normally, the spindle motor and its drive circuit are combined into one, called the spindle signal path. This circuit also consists of a connecting line that is the same as the laser signal path. Connection, but the number of strands is different. Because the information path between it and the laser head is communicated by the servo circuit. Therefore, there are many similarities in fault phenomena. However, since the connecting wire of the laser head information path is easily broken and damaged when entering and exiting the box, when encountering the same fault phenomenon, you should first consider the fault of the laser head information path. Then consider the spindle signal path failure.

Troubleshooting symptoms caused by laptop keyboard failure

The main problem with laptop computers is that they cannot be turned on.

The notebook crashes from time to time during use.

A certain key on the laptop keyboard does not work.

Hardware failure phenomenon

1. No power (power indicator light does not light up)

1. Check whether the external adapter is correctly connected to the notebook, and whether the external adapter is properly connected to the notebook. Works fine.

2. If you only use the battery as the power source, check whether the battery model is the original battery; whether the battery is fully charged; and whether the battery is installed correctly.

3. Check whether the DC board is normal;

4. Check and repair the motherboard

2. The power indicator light is on but the system is not running and the LCD has no display< /p>

1. Press and hold the power switch for four seconds to turn off the power, then restart it to check whether it starts normally.

2. Check whether the external CRT monitor displays normally.

3. Check whether the memory is plugged in securely.

4. Clear CMOS information.

5. Try to replace the memory, CPU, and charging board.

6. Repair the motherboard

3. The displayed image is not clear

1. Check whether the display brightness is normal after adjusting it.

2. Check whether the display driver is installed correctly; whether the resolution is suitable for the current LCD size and model.

3. Check whether the LCD cable and the motherboard are connected correctly; Check whether the LCD cable and the LCD are connected correctly.

4. Check whether the backlight control board is working properly.

5. Check whether there is cold soldering or virtual soldering on the Northbridge chip on the motherboard.

6. Try replacing the motherboard.

4. No display

1. Check whether the system is in hibernation state through the status indicator light. If it is in hibernation state, press the power button to wake it up.

2. Check whether the external monitor is connected normally.

3. Check whether the power supply is connected.

4. Check that both ends of the LCD cable are connected properly.

5. Replace the backlight control board or LCD.

6. Replace the motherboard.

5. The battery power is not recognized properly in Win98/Win Me

1. Confirm that the power management function is enabled in the operating system and is set correctly.

2. Charge the battery for three hours before use.

3. Charge and discharge the battery twice in Windows 98 or Windows Me.

4. Replace the battery.

6. The touchpad does not work

1. Check whether an external mouse is connected and use the MOUSE test program to check whether it is normal.

2. Check whether the touchpad cable is connected correctly.

3. Replace the touch panel

4. Check the keyboard control chip for cold soldering and virtual soldering

5. Replace the motherboard

< p>7. The serial port device does not work

1. Check whether the serial port is set to "ENABLED" in the BIOS settings

2. Use the SIO test program to check whether it is normal.

3. Check whether the serial device is connected correctly.

4. If it is a serial mouse, check whether the built-in touchpad is turned off in the BIOS settings; check whether the serial mouse is recognized in the device manager of Windows 98 or Me; check whether the serial mouse driver is installed correctly.

5. Replace the serial port device.

6. Check whether there is cold soldering or virtual soldering on the south bridge chip on the motherboard.

7. Replace the motherboard.

8. The parallel port device does not work

1. Check whether the parallel port is set to "ENABLED" in the BIOS settings.

2. Use the PIO test program to check whether it is normal.

3. Check whether all connections are correct.

4. Check whether the external device is turned on.

5. Check whether the printer mode setting is correct.

6. Check whether there is cold soldering or virtual soldering on the south bridge chip on the motherboard.

7. Replace the motherboard.

9. The USB port does not work

1. Check whether the USB port is set to "ENABLED" in the BIOS settings.

2. Re-plug the USB device and check whether the connection is normal.

3. Check whether the USB port driver and USB device driver are installed correctly.

4. Replace the USB device or contact the USB device manufacturer for technical support. "ENABLED"

5. Replace the motherboard.

10. The sound card is not working properly

1. Use the AUDIO detection program to check whether it is normal.

2. Check whether the volume adjustment is correct.

3. Check whether the sound source (CD, tape, etc.) is normal.

4. Check whether the sound card driver is installed.

5. Check whether the speaker and microphone connections are normal.

6. Replace the sound card board

7. Replace the motherboard.

11. Fan problem

1. Use the FAN test program to check whether it is normal and whether the fan is normal when turning on the computer

2. Is the FAN cable plugged in?< /p>

3. Is the FAN in good condition?

4. Is the CONNECTER in the M/B part soldered well?

5. The motherboard is defective

10 2. KB problem

1. Use KB test program to test and judge

2. Is the keyboard cable plugged in properly?

3. Is the CONNECTER of the M/B part correct? There are crooked pins or other defects

4. Defective motherboard

Classification of software faults

13. Driver category

1. The display is abnormal;

2. The sound card does not work;

3. Modem and LAN do not work

4. QSB does not work

5. Some hardware cannot be used normally because the driver is not loaded or the driver is loaded incorrectly

14. Operating system categories

1. The operating system slows down

2. Sometimes it freezes

3. The model does not support a certain operating system

4. It cannot shut down normally

5. It freezes during hibernation

15. Application categories

1. Application conflicts cause the system to crash

2. Applications cause the system to fail to shut down normally

3. Application conflicts lead to inability to use normally

1. Battery usage issues

1. Does a new battery need to be charged for 12 hours like a mobile phone?

Although the circuit design of laptop computers is much more perfect than that of mobile phones, in order for the new battery to work in a better state, battery activation and calibration still need to be carried out. The common practice among manufacturers is to The battery should have 3% power when the notebook is turned on for the first time. At this time, you should not use the external power supply first, but use up the remaining power in the battery until it shuts down, and then use the external power supply to charge. Then you have to recharge the battery after it is exhausted. The charging time must be more than 12 hours and repeated three times to activate the battery.

2. Why is the battery usage reduced even when the battery is not in use?

Due to the influence of ambient humidity and non-absolute insulation environment, batteries are subject to natural consumption. Depending on the age and quality of the battery, it will decrease by about 1% in 3-4 days, so as long as it is not drastically Any decrease is normal.

3. Do I need to remove the battery to use the power supply?

The charging design of general laptop computers is to charge when the power is lower than 95%, and due to the existence of natural loss, the loss of the battery is basically the same whether it is removed or not. , so whether to remove it or not depends on your habits. If you remove it, it is recommended to wrap the battery in plastic wrap and place it in a dry and cool place. Remember to use and charge the battery at least once a month to avoid battery loss of activity.

4. Will charging the battery before it is completely used up reduce its lifespan?

Battery life is generally calculated based on the number of full charges. Li batteries are generally 300-400 times. Of course, you don’t have to worry about plugging in the power supply and charging the battery once. Even just a little charge will be counted once. The number of charging times of the battery will generally only increase once when the battery is charged to 80-90%, so don’t worry. I would also like to mention here that laptop batteries usually use lithium batteries, so avoid using lithium batteries in high-temperature environments. According to expert research, high temperatures will accelerate the aging process of lithium batteries, and similarly, do not use them in extreme low-temperature environments. Use below. Low-temperature environments will reduce the activity of lithium batteries and reduce the life of laptop batteries. Regularly activate the lithium battery, which means fully charging and discharging it, so that the lithium battery can restore its maximum capacity. The method is to turn off all power management, let the notebook slowly discharge until it is completely empty, and then fully charge it, repeat two to three times. In hot weather, maintain your own laptop battery as much as possible so that your laptop can play its role better.

2. Laptop cooling issues

At present, laptops generally use three-stage cooling methods: heat pipe cooling, keyboard convection cooling, and temperature-controlled fan cooling. Personally, I think IBM and Toshiba are more technologically advanced, although Toshiba's books are not favored by many people.

1. Why does the fan spin once and then stop spinning when it is turned on?

Due to the temperature control design of the laptop, the fan will stop rotating after self-checking when it is turned on. It will only accelerate when the temperature inside the machine reaches a certain temperature. This is why when you perform high-load work, such as The reason why the fan rotates at high speed when playing high decoding rate videos, 3D games, etc.

2. Should I pay attention to the surrounding environment when using a laptop?

When using a notebook, you should pay attention to the cleanliness of the surrounding environment. Usually, the ideal working temperature of the notebook is 10℃~35℃, and the humidity should not be too high. Especially in the hot summer, keep the surrounding environment well ventilated and try to use your laptop in an air-conditioned room. Grooves and openings in the computer case are used for ventilation.

To ensure reliable operation of the computer and prevent overheating, do not block or cover these openings. Do not place the computer on your legs, on the bed or on the sofa. These are not advisable. Soft objects will block the heat dissipation holes at the bottom of the notebook, preventing the heat from being dissipated smoothly and causing malfunctions. You can place some books or the like (sometimes black tea bottle caps are used) on the bottom of the machine from the rear end to keep some space between the bottom of the notebook and the desktop, so that the bottom of the notebook will not stick to the desktop. This will allow more heat to dissipate from the bottom, or you can add a heat dissipation base to increase the airflow speed at the bottom of the notebook. There are also some external cooling equipment on the market, such as USB flash drives or built-in cooling modules, but I haven't used them yet.

3. Close the laptop:

When you have finished your work, close the laptop and try to give your laptop a good rest.

Don’t leave your laptop open in your bag

. Clean the vents frequently. Laptops have built-in fans with vents. Over time, dust can accumulate in the vents, which can clog them.

At the same time, if necessary, you can use a diagnostic tool to test whether the notebook fan is working properly. If you have special tools, you can also open the fan area and remove the dust.

4. Upgrade the laptop's BIOS:

Sometimes, heat means that the computer fan controller needs a BIOS upgrade. The new version of BIOS can make notebook fans work more efficiently. If you feel that your laptop is getting hotter, you may wish to check the website to see if a new BIOS is available.

The heat dissipation of notebooks is not perfect yet. As the functions become more powerful, the heat generated will increase, which also puts pressure on the cooling system. General notebook problems should be detected with professional software, such as In today's weather (room temperature is around 30 degrees Celsius), it is normal for the temperature of the CPU and hard disk to be above 60 degrees Celsius.

3. Screen problems

1. Bright pixels and dead pixels

The so-called dead pixels refer to uncontrollable constant bright or dark spots on the LCD screen. Dead pixels are caused by defects caused by various factors during the production of LCD panels. For example, it may be some tiny particles falling into the panel, it may be damage caused by static electricity, or it may be poor process control, etc.

Dead pixels are divided into two types: bright pixels and dark pixels. A bright spot is a point that is always bright in any screen, and can be found by switching to a black screen; a dark spot is a point that is constantly dark in any screen, and can be found by switching to a white screen. Generally, when you just buy a laptop or when you buy it, you can use software to detect the bright spots or dead pixels on the screen. Generally, the standards for this vary depending on the brand, and generally there can be no more than three. For detection software, just use MonitorTest. At the same time, you should reduce the possibility of the screen being exposed to sunlight. When using it during the day, try to close the curtains to prevent the screen from being exposed to sunlight and the temperature will accelerate aging

2. How to wipe the screen

If it is just dust, you can first blow away the dust as much as possible with an air blower, and then wipe it with a damp soft cloth. The soft cloth should be wrung out, otherwise water may flow into the high-voltage package along the screen surface and cause damage to the screen. . If it is oil stains or stains that are difficult to remove, you can buy a special cleaner for LCD screens to remove them. Remember not to use cleaners without quality assurance, otherwise corrosive chemical components such as alcohols will cause damage to the screen. Zhongguancun usually sells notebooks with a bright and clean cleaning kit, so you can use this one. Don’t: Do not wipe the screen with your hands or hard objects.

3 Do I need to apply film?

I do not recommend applying a film. Although the screen film will protect it, this location is generally inaccessible. The composition of the film itself will cause certain damage to the screen and affect heat dissipation.

4. Sometimes the screen will make a squeaking sound when using the battery

Generally the latest notebooks do not have this problem, but older computers or better quality computers will have this problem. This problem needs to be explained from two aspects: First, when the battery is powered, due to the energy-saving characteristics of the notebook computer, the voltage of the entire notebook circuit is constantly changing. At this time, the voltage in the screen high-voltage package is energized. The current of the coil is constantly changing, and the frequency conversion sound emitted by the high-voltage coil at this time is also involved in middle school physics knowledge. If the electromagnetic shielding of the notebook computer is poor, this sound will be heard by the user. Therefore, we say that this phenomenon is more common in notebook computers of some brands with weak technical foundation. In fact, many friends reported that the power adapter produces sound as well. Caused by this reason. Secondly, this sound may also be high-frequency noise. The biggest difference between this sound and the sound mentioned in Part 1 is that high-frequency noise is a kind of crazy sound. I believe friends who have heard this sound will Have some experience. Generally, this sound is a motherboard design defect. If the situation is common, the manufacturer will release a BIOS update file to solve this problem. For example, the recent IBM T40 and HP NC6000 have this problem to varying degrees, and the manufacturer has also released a new BIOS for this problem. solve.

2012-7-20 9:38:03s brake5054634263rsivsmzzyh7825116634qсédingxrgd