The computer always has a clear screen, only the desktop is still there, and the logo is gone. What happened?

Complete collection of common notebook faults

Due to the particularity of notebook computer structure, its maintenance is more complicated. But after all, notebook computer is a kind of computer, and its maintenance principle is basically the same as that of ordinary desktop computer. If you are a notebook computer user and are interested in its maintenance knowledge, you can refer to this article, which lists some analysis and handling processes to solve notebook computer faults, which may be helpful to you.

Notebook Common Faults-Boot Failure-Hardware Judgment

-The BIOS failure of the laptop motherboard will cause the laptop not to turn on.

-The laptop's CPU is out of order, and the laptop's LCD screen is unresponsive, which is also the reason why it is not turned on.

-The failure of the signal output port of the notebook computer will lead to the power-on failure.

-The failure of the control chip of the motherboard graphics card of the notebook computer will cause the computer to fail to boot.

-Failure of the laptop graphics card will cause the laptop not to turn on.

-Memory failure of the laptop will cause it to turn off.

Whether the notebook battery can be charged-hardware fault judgment

-The failure of the laptop power adapter will cause the battery to fail to charge.

-A laptop battery failure will cause the battery to fail to charge.

-The battery can't be charged due to the failure of the power control chip of the laptop motherboard.

-The failure of other lines on the motherboard of the notebook computer will cause the battery to fail to charge.

Notebook does not recognize peripherals-hardware fault judgment

-The failure of the peripheral hardware related to the notebook computer will make the notebook unable to recognize the peripheral.

-The laptop BIOS is faulty, and the wrong setting will make the laptop unable to recognize the peripherals.

-The failure of the interface related to the peripherals on the laptop motherboard will cause the laptop to deny the peripherals.

-Failure of the motherboard of the notebook computer will also cause the notebook computer to fail to recognize peripherals, and the notebook computer cannot be turned on at the same time.

Failure of notebook motherboard will cause the following phenomena and characteristics.

-The notebook computer does not recognize the notebook hard disk after it is turned on.

-The notebook computer can't recognize the notebook optical drive after being turned on.

-The laptop battery is not charged.

-Turn off the laptop regularly or irregularly.

-The laptop keyboard is broken.

-Laptops sometimes lose power when turned on.

-Laptops often crash.

These failures are all related to the notebook motherboard.

Failure phenomenon caused by notebook power adapter

-The laptop won't open.

-The laptop crashes intermittently.

-The notebook power adapter is hot.

-When reading a DVD, the optical drive of a notebook computer can easily crash or lose power.

-Laptops are prone to crash or power failure when running large programs.

These failures are all related to the notebook power adapter.

Introduction of notebook optical drive

Notebook optical drive-mechanical drive part.

Notebook optical drive-laser head assembly.

The failure of notebook optical drive mainly comes from these two parts (notebook optical drive).

1. The drive mechanism is mainly composed of three small motors: the disc loading mechanism is composed of motors that control the loading and unloading of the cassette, and mainly completes the loading (loading) and unloading (unloading) of the optical disc; The feed mechanism of the laser head is driven by the feed motor, which completes the smooth movement of the laser head from inside to outside or from outside to inside along the radial direction of the optical disc, so as to quickly read the data of the optical disc; The spindle rotating mechanism is mainly driven by the spindle motor to complete the rotation of the optical disc, and generally adopts DD control mode, that is, the rotating shaft of the optical disc is the rotating shaft of the spindle motor.

Second, the laser head assembly is the most important and fragile part of all kinds of optical drives. The main types are single beam laser head, three (multi) beam laser head, holographic laser head and so on. It is actually a whole, and the common single-beam laser head is mainly composed of semiconductor laser, semi-transparent prism/collimator lens, photosensitive detector and actuator.

Analysis of Common Faults of Notebook Optical Drive

The most common fault of notebook CD-ROM drive is mechanical fault, followed by circuit fault. The fault caused by improper adjustment of users is much more than the fault of component damage, so when disassembling or repairing CD-ROM drive equipment, don't adjust all kinds of potentiometers inside notebook CD-ROM drive casually.

There are three common faults of notebook optical drive: operation fault, accidental fault and inevitable fault.

1. The notebook CD can't be found under Windows or DOS due to operation failures such as driver error or incorrect installation; Notebook CD-ROM drive can't be used because of wrong connecting cable or jumper; You can't listen to the CD because the CD cable is not connected correctly; The notebook CD-ROM drive is not properly placed on the tray, which makes the CD-ROM drive unable to read the disc; Distortion or dirt of the optical disc leads to unclear or paused picture, or serious mosaic phenomenon; Improper disassembly leads to the breakage or looseness of various wires inside the CD-ROM drive, leading to failure, etc.

2. Unexpected failures Random failures of notebook optical drives, such as early failures or sudden damage of internal integrated circuits, capacitors, resistors, transistors and other components, or sudden damage of some mechanical parts with frequent actions, are rare, but they must be repaired and replaced before they can be eliminated, so unexpected failures are also called "true" failures.

3. Inevitable failures The inevitable failures of the notebook optical drive after a period of use mainly include: the aging of the laser diode, the longer reading time, and even the inability to read the disk; The optical lens in the laser head assembly is dirty/poor in performance, resulting in audio/video distortion or collapse; Mechanical transmission mechanism fails due to wear, deformation and looseness.

It should be noted that the maintenance rate of inevitable failures depends not only on the quality of products, but also on the manual operation and maintenance, frequency and environment of users.

Judgment of common faults

1. If the CD-ROM drive is not detected at startup, please check whether the jumper of the CD-ROM drive is correct. Then check whether the IDE interface of the CD-ROM drive is plugged in. If not, you can plug it in again. Finally, it is possible that the data cable is damaged.

2. The failure of entering and leaving the box is characterized by not entering or leaving the box smoothly. The possible reasons and troubleshooting methods are: the pin contact of the motor entering and leaving the box bin is poor or the motor is burnt out-it can be reinserted or replaced; The transmission belt (rubber band) in the mechanical structure of the box is loose and slippery.

3. The failure of the laser head is manifested as picking disks (some disks can be read and some disks cannot be read) or poor disk reading ability. When the optical drive is used for a long time or often used to watch VCD or listen to CD, the objective lens of the laser head becomes dirty or aging.

★ Please don't use some cheap and inferior optical cleaning discs sold in the market, because the bristles of these discs are too hard, which will scratch the objective lens, and may also cause electrostatic hazard and shorten the service life of the optical drive.

4. Laser signal path failure refers to the connecting 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 failures here. .

5. Spindle signal path failure In general, the spindle motor and its driving circuit are integrated into one, which is called spindle signal path. This circuit is also connected by the same connecting wire as the laser signal path, but the number of strands is different. Because it communicates with the information path of the laser head through the servo circuit. Therefore, there are many similarities in the fault phenomena, except that the connecting line of the information channel of the laser head is easy to be pulled off when entering and leaving the box. Therefore, when encountering the same fault phenomenon, the fault of the information channel of the laser head should be considered first, and then the fault of the spindle signal channel should be considered.

Failure phenomenon caused by notebook keyboard failure.

The main fault in the use of notebook computer is that it can't be turned on.

Notebooks sometimes crash during use.

One of the keys of the laptop keyboard is not working properly.

Hardware failure phenomenon

First, there is no electricity (the power indicator light is not on)

1. Check whether the external adapter is properly connected with the notebook and whether the external adapter works normally.

2. If only the battery is used as the power supply, check whether the battery model is the original battery; Whether the battery is fully charged; Whether the battery is installed correctly.

3. Check whether the DC board is normal;

4. Check and repair the motherboard

Second, the power indicator is on, but the system is not running, and the LCD screen is not displayed.

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

2. Whether the external CRT display is normal.

3. Check whether the memory is plugged in.

4. Clear CMOS information.

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

6. Repair the motherboard

Third, the displayed image is not clear.

1. Check whether the brightness of the display is normal after adjustment.

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

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

4. Check whether the backlight control panel works normally.

5. Check the North Bridge chip on the motherboard for cold welding and virtual welding.

6. Try to replace the motherboard.

Fourth, there is no display.

1. Check whether the system is in hibernation by the status indicator. If it is dormant, 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 whether both ends of LCD cable are connected normally.

5. Replace the backlight control panel or LCD screen.

6. Replace the motherboard.

Verb (abbreviation of verb) can't recognize the battery capacity normally in Win98/Win Me.

1. Confirm that the power management function has been started in the operating system and set correctly.

2. Before using, charge the battery for three hours.

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

4. Replace the battery.

Sixth, the touchpad doesn't work.

1. Check whether there is an external mouse connection, and use the mouse test program to check whether it is normal.

2. Check whether the touchpad is connected correctly.

3. Replace the trackpad

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

5. Replace the motherboard

Seven, the serial port device does not work.

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

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

3. Check whether the serial port device is connected correctly.

4. If it is a serial mouse, check whether the built-in touchpad is turned off in 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 the South Bridge chip on the motherboard for cold welding and virtual welding.

7. Replace the motherboard.

Eight, parallel port equipment does not work

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

2. Check whether it is normal with PIO test program.

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 the South Bridge chip on the motherboard for cold welding and virtual welding.

7. Replace the motherboard.

Nine, USB port does not work

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

2. Plug and unplug the USB device again 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.

X. The sound card is not working properly.

1. Check whether it is normal with audio detection program.

2. Check whether the volume adjustment is correct.

3. Check the sound source (CD, tape, etc. ) It's normal.

4. Check whether the sound card driver is installed.

5. Check whether the speaker and microphone are connected properly.

6. Replace the sound card board

7. Replace the motherboard.

XI。 Fan problem

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

2. Is the fan cable plugged in?

3. Is Fan good?

4. Is the M/B connector welded well?

5. Bad motherboard

Twelve. KB problem

1. Test and judge with KB test program.

2. Is the keyboard cable plugged in?

3. Is there any bent pin or other defects in the connector of M/B part?

4. Bad motherboard

Classification of software faults

Thirteen. Driver class

1. The display is abnormal;

2. The sound card does not work;

3. Modem and LAN can't work

4.QSB cannot be used.

5. Some hardware can't be used normally because the driver is not loaded or loaded incorrectly.

Fourteen Operating system category

1. The operating system is slow.

2. Sometimes it will collapse

3. This model does not support the operating system.

4. Unable to shut down normally

5. Hibernation crash

Fifteen, the application class

1. System crashed due to application conflict.

2. The application causes the system to fail to shut down normally.

3. Application conflict leads to abnormal use.

I. battery usage issues

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

Although the circuit design of notebook computer is much better than that of mobile phone, in order to make the new battery work in a better state, it is still necessary to activate and calibrate the battery. The general practice of manufacturers is that the battery of new notebook should have 3% power when it is turned on for the first time. At this time, the external power supply should not be used first, but the remaining power in the battery should be exhausted until it is turned off, and then the external power supply should be used for charging. Then charge the battery after the battery is exhausted. The charging time must be more than 12 hours, and the battery can be activated only after repeated three times.

2. Why is the battery useless and the power consumption reduced?

Due to the influence of environmental humidity and non-absolute insulation environment, the battery is naturally consumed. Depending on the battery's newness and quality, it will probably drop by about 1% in 3-4 days, so it is normal as long as it does not drop significantly.

3. Do I need to take out the battery when using the power supply?

The charging design of notebook computers generally only charges when the power is less than 95%. Moreover, due to the existence of natural loss, the battery loss is basically the same as that without disassembly, and whether it is disassembled depends on habits. If removed, it is recommended to wrap the battery with plastic wrap and put it in a dry and cool place, and remember to use the battery at least once every 65,438+0 months to avoid battery deactivation.

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

The life of a battery is generally calculated according to the times of full charge, and the lithium battery is generally 300-400 times. Of course, you don't have to worry about charging the battery once, even if it is only one point, it will be counted once. Generally, the charging times of the battery will only increase once when the accumulated power reaches 80-90%, so don't worry. I also want to say that notebook batteries generally use lithium batteries, so avoid using lithium batteries in high temperature environment. Experts have studied that high temperature will accelerate the aging process of lithium batteries, and do not use them in extremely low temperature environment. Low temperature environment will reduce the activity of lithium battery and the life of notebook battery. Activate the lithium battery regularly, that is, fully charge and discharge, so that the lithium battery can restore its maximum capacity. The method is to turn off all power management, let the notebook discharge slowly until it is completely dead, then fully charged, and repeat it two or three times. In hot weather, take care of your notebook battery as much as possible, so that the notebook computer can play a better role.

2. Notebook heat dissipation problem

At present, notebooks generally adopt three-stage heat dissipation methods: cooling pipe heat dissipation, keyboard convection heat dissipation and temperature-controlled fan heat dissipation. Personally, I think IBM and Toshiba are more advanced in technology, although Toshiba's notebooks are not favored by many people.

1. Why does the fan turn once when it is turned on and never turn again?

Because of the temperature control design of the notebook computer, the fan will stop rotating after the self-test, and will only accelerate when the computer reaches a certain temperature, which is why the fan will rotate at a high speed when you are doing high-load work, such as playing high-decoding video and 3D games.

2. Should we pay attention to the surrounding environment when using the notebook?

When using a notebook, you should pay attention to the cleanliness of the surrounding environment. Usually, the ideal working temperature of notebook is 10℃~35℃, and the humidity should not be too high. Especially in hot summer, we should keep the surrounding environment well ventilated and try to use notebooks in air-conditioned rooms. Grooves and openings in the computer case are used for ventilation. To ensure that the computer can work reliably and prevent overheating, please don't block or cover these openings. Please don't put the computer on your lap, bed or sofa. It's not advisable. Soft things blocked the cooling hole at the bottom of the notebook, which made the heat of the notebook unable to be smoothly exported, leading to failure. You can put some books on the bottom of the machine from the back end (occasionally use the bottle cap of black tea), and leave some space between the bottom of the notebook and the desktop, so that the bottom of the notebook will not be close to the desktop. This will emit more heat from the bottom, or you can add a cooling base to increase the airflow speed at the bottom of the notebook. There are also some external cooling devices on the market, similar to USB flash drives or built-in cooling modules, but I have never used them.

3. Close the notebook:

When you finish your work, close your notebook and try to have a good rest.

When your notebook is opened, don't leave it in the bag.

. Always clean the vents, and the fans in the notebook have vents. After a while, dust will accumulate in the vents and block them.

At the same time, if necessary, you can use diagnostic tools to test whether the fan of the notebook works normally. If you have special tools, you can also turn on the fan to clean up the dust.

4. Upgrade the BIOS of the notebook computer:

Sometimes, fever means that the controller of the computer fan needs BIOS upgrade. The new BIOS can make the notebook fan work more efficiently. If you think your notebook is getting hotter, you might as well go to the website to see if there is a new BIOS.

The heat dissipation of notebook is not perfect. Powerful, calorific value will be greater, which also brings pressure to the cooling system. General notebook problems are detected by professional software. It is normal that the temperature of CPU and hard disk is above 60 degrees in this weather (the room temperature is around 30 degrees).

Three. Screen problem

1. Highlights and Disadvantages

The so-called bad point refers to the point on the LCD screen that is uncontrollable and constantly bright or dark. The causes of bad spots are the defects caused by various factors in the production process of LCD panel, such as some fine particles falling into the panel, electrostatic damage to the panel, poor process control and so on.

There are two kinds of bad spots: bright spots and dark spots. A bright spot is a bright spot in any picture, which can be found by switching to a black picture; A dark spot is a spot that is always dark in any picture. You can find it by changing it to a white map. You usually buy a notebook you just bought, and use software to detect the bright spots or bad spots on the screen. Generally speaking, according to different brands, there are different standards for this, generally no more than three. MonitorTest is enough for testing software. At the same time, it is necessary to reduce the possibility of the screen being exposed to the sun at ordinary times. When using it during the day, try to close the curtains to prevent the screen from being exposed to the sun.

2. How to clean the screen

If it's just dust, you can blow the dust away as much as possible with a hair dryer, then wipe it with a wet soft cloth and wring it out, otherwise water may flow into the high-pressure bag along the screen surface, causing screen damage. If it is oily or difficult to remove stains, you can buy a special cleaner for LCD screen to remove them. Remember not to use cleaning agents without quality assurance, or corrosive chemicals such as alcohol will damage the screen. The notebooks generally sold in Zhongguancun are bright and clean cleaning suits. You can use this. Avoid: Do not wipe the screen with your hands or hard objects.

3 Do you want to film it?

I don't recommend sticking film. Although the screen sticking film will play a protective role, this position is generally harmless, and the composition of the sticking film itself will do some harm to the screen and affect the heat dissipation.

Sometimes the screen squeaks when the battery is used.

Generally, the latest notebook will not have this problem, but older computers or quality departments will have this problem. This problem needs to be explained from two aspects: first, when the battery is powered on, the voltage of the whole notebook circuit is constantly changing due to the energy-saving characteristics of the notebook computer, and the current passing through the electrified coil in the screen high-voltage bag is also 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 notebook computers is poor, users will hear this sound, so we say this phenomenon is more common in some notebook computers with weak technical foundation. In fact, many friends report that the power adapter will produce sound, which is also caused by this reason. Secondly, this sound may also be high-frequency noise. The biggest difference between this sound and the above is that high-frequency noise is a maddening sound, which I believe friends who have heard will understand. Generally, this kind of sound belongs to the design defect of the motherboard. If this 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 manufacturers have also released new BIOS to solve it.

2012-7-2216: 02: 55h survey153281tnweflgzq1058343886g.