"It is better to have an antistatic wrist strap for leather, detergent or computer-specific cleaning towel.
unscrew the screws that secure the chassis and open the chassis. It must be dirty inside. Think about it. When your laptop is working, the three cooling fans installed on the power box, cpu and graphics card are running at the same time, which sucks in air to cool down the hardware and brings in a lot of dust at the same time. It is amazing to accumulate over time. There are nothing more than power boxes, various expansion cards (including graphics cards, sound cards and network cards, etc.), memory sticks, fans on cpu and graphics cards, motherboards and the chassis itself to be cleaned up. Let's start with the power box. Because the computer's exhaust cooling is mainly * it, the dust falling on it is the most. In order to clean thoroughly,
for the heat sink, just wash it with water and dry it, but be careful not to lose the heat-conducting silica gel on the surface. Next, check the motherboard, and carefully check whether there are "bulge" and "Explosicum" on the top of the "electrolytic capacitor" on the motherboard.
if yes, the motherboard will be sent to the maintenance department. If the motherboard is not very dirty, there is no need to remove it and clean it. Brush the dust directly between the slots, components and the panel with a soft pen, and then blow it with a hair dryer and a vacuum cleaner for several times.
The cleaning of the chassis itself is much easier. Wipe off the dust and dirt in the chassis directly with a soft cloth. Finally, put the removed parts back in their original positions, and then install the case cover to call it a day. Looking at this brand-new machine, do you have a sense of accomplishment? _
don't wash it! Even if you use anhydrous alcohol, it is easy to go wrong! I suggest you take it down and clean it with a brush that doesn't remove hair! Wipe your golden fingers a few times with your hands or some toilet paper! (that is, the memory module, these parts that are linked to the motherboard)
Of course, more dust will have a certain impact! But limited!
If there is too much dust, it will probably damage the hardware of the computer. Just open the main chassis, don't move anything, brush it with a brush, use a hair dryer, or blow the dust with your mouth. That's what I did! ! ! Don't touch the water, if you use water to wash it, it's useless to make a guarantee! !
Open the computer case, use a vacuum cleaner, and gently brush off the dust with a long brush at the same time. The dust is mostly in the power supply. If the power supply is too loud, it means that the fan needs to refuel. After disassembling it, you will understand it slowly.
Microcomputer host dust removal and board maintenance
Microcomputer is a high-precision equipment. Besides correct use, daily maintenance is also very important. In the long-term maintenance work, the author found that a large number of failures are caused by lack of daily maintenance or improper maintenance methods. This series of articles comprehensively introduces the disassembly and routine maintenance methods of each part of the microcomputer system, aiming at helping microcomputer users to maintain their own computers by themselves, so as to nip in the bud. This paper is the first article in this group, which mainly introduces the common maintenance tools, maintenance precautions, the removal of wiring in each part of the main chassis, the dust removal inside the chassis and the routine maintenance methods of the board.
1. Maintenance tools:
Computer maintenance doesn't need complicated tools, and general dust removal maintenance only needs to prepare a cross screwdriver, a flat screwdriver and a paint brush (or an oil brush, which is easy to depilate but not suitable for use). If you want to clean the inside of floppy drive and CD-ROM drive, you need to prepare lens wipes, hair dryer, anhydrous ethanol (analytical pure), absorbent cotton balls, a set of clock screwdriver, tweezers, balloon blowing (leather tiger), paper clips, clock oil (or sewing machine oil) and butter. If further maintenance is needed, prepare a needle-nosed pliers, a electroprobe and a multimeter.
second, maintenance precautions
some
when fixing the components with screws, the positions of the components should be aligned first, and then the screws should be tightened. Especially the motherboard, a slight position deviation may lead to poor contact of the card; The uneven installation of the motherboard may lead to poor contact between the memory module and the adapter card or even short circuit, which may even deform over time and lead to failure;
Because most integrated circuit devices on computer boards are manufactured by MOS technology, such semiconductor devices are quite sensitive to electrostatic high voltage. When people or things with static electricity touch these devices, static electricity will be released, and the released static high voltage will damage
(1) Disconnect all power supplies;
(2) Before opening the chassis, you should touch the ground or the wall with your hands to release the static electricity. When holding the motherboard and card, try to hold the edge of the card, and don't touch the integrated circuit of the card with your hands. If you must touch the internal circuit, it is best to wear a grounding ring;
(3) Please don't wear rubber shoes that are easy to rub with the floor and carpet to generate static electricity. Wearing metal shoes can release static electricity on people well, and anti-static floors should be used in qualified workplaces;
(4) keeping a certain humidity, air drying is easy to generate static electricity, and the ideal humidity should be 4%-6%;
(5) When using electric soldering irons and electric fans, the grounding wire should be properly connected.
III. Dismantling the host computer
Unplug the peripheral wiring
After turning off the power switch and unplugging the power cord, you can begin to disassemble the host computer. The first step in disassembling the host computer is to unplug all the peripheral wiring at the back of the chassis.
There are two main ways to unplug the connection between the peripheral and the computer. One way is to directly pull the plug outward and unscrew a few screws with a Phillips screwdriver to remove the chassis cover.
remove the adapter card
insert the display card and sound card into the expansion slot of the motherboard and screw them to the bar on the back of the chassis
unplug the drive data cable
There are two points to pay attention to when unplugging the drive data cable from the hard disk. First, don't pull the data cable down. There are mostly 1 signs next to the interface socket of the actuator.
Unplug the power plug of the drive
The power plug of the hard disk and CD-ROM drive is a big four-pin plug, and the power plug of the floppy drive is a small four-pin plug. Just pull it out horizontally. Please pay attention to the direction when installing and restoring. Generally, it is impossible to insert it in the reverse direction. Forcibly inserting it in the reverse direction will damage the drive after connecting the power.
remove the drive
the hard disk, floppy disk and CD-ROM drive are all fixed on the drive bracket in the chassis panel. When removing the drive, please unscrew the screws on both sides of the drive bracket (some fixing screws are on the panel) before pulling out the drive forward. Unscrew the hard disk and unplug the motherboard power plug
The power plug is plugged into the motherboard power socket. The ATX power plug is a double-row 2-pin plug with a small plastic card. You can unplug the ATX power plug by pinching it. AT power plugs are two six-pin plugs P8 and P9, which can be pulled up smoothly. Finally, please pay attention to the direction when restoring the AT power plug. The black line between the six-pin plugs P8 and P9 should be inserted down together, and the wrong direction will lead to a short circuit of the power supply.
Other plugs
The plugs that need to be unplugged may include the CPU fan power plug, and the dust in the audio between the CD-ROM drive and the sound card is generally cleaned with an oil painting pen first, and then blown out with a balloon or a hair dryer.
if there is oil stain on the metal pins in the socket, it can be removed with absorbent cotton balls dipped in computer-specific cleaning agent or anhydrous ethanol. The computer-specific cleaning agent is mostly carbon tetrachloride plus active agent.
VI. Cleaning CPU fans
PII and Celeron CPU are relatively new at present, so the fans generally don't need to be taken down, just use a paint brush or oil painting pen to clean them. There is a lot of dust on the older CPU fan, so it is generally necessary to take it down and clean it. Taking the CPU of Socket 7 as an example, this paper introduces the dust removal of CPU fan.
the bulk CPU fan is stuck on the buckles on both sides of the CPU socket. Press the fan buckle slightly to remove the CPU fan. After removing the CPU fan, dust can be removed from the fan. Note that there is a lot of dust in the seam of the heat sink.
the original CPU fan is integrated with the CPU, so it is necessary to gently pull the handle beside the Socket 7 to the outside to separate the handle from the handle locating card, and then push it up to the vertical position of 9 degrees, and then remove the CPU upward. When cleaning the CPU fan, be careful not to dirty the heat-conducting silica gel between the joint surface of CPU and heat sink.
VII. Cleaning the memory stick and adapter card
Cleaning the memory stick and various adapter cards includes dust removal and cleaning the gold finger on the circuit board. Just use an oil painting pen for dust removal. The gold finger is the connection point between the circuit board and the socket. If there is dust, oil pollution or oxidation, it will cause poor contact. A large number of faults in old microcomputers come from this. The gold fingers of advanced circuit boards are gold-plated and are not easy to oxidize. In order to reduce the cost, the gold fingers of general adapter cards and memory chips are not plated with gold, but only a layer of copper foil, which will be oxidized after a long time. Eraser can be used to wipe the dust, oil stain or oxide layer on the surface of the gold finger. Never use sandpaper to wipe the gold finger, otherwise it will damage the extremely thin coating.
Dismantling and maintenance of the optical drive-cleaning the focusing lens, laser head and laser power adjustment
The optical drive is an essential basic configuration of multimedia computers. In actual use, there are many times when the optical drive fails. When the optical drive fails at first, it usually picks the disk, and it becomes more and more serious in the future until it can't read the disk. This kind of fault is usually caused by the dust accumulation in the focusing lens and laser head or the aging of laser tube. Therefore, after the failure of reading the disk, the optical head can be cleaned first, including general dust removal and cleaning of the focusing lens and laser head. If the fault still cannot be eliminated, it may be caused by poor contact of the laser current regulating potentiometer or aging of the laser diode, which can be solved by adjusting the potentiometer. Most of the failed CD-ROMs that the author handled were repaired by the above methods. Taking SONY CDU311 eight-speed optical drive as an example, this paper introduces the methods of disassembling the optical drive, cleaning the focusing lens, laser head and adjusting the laser power.
CD-ROM drive is a high-precision device integrating optics, electricity and machinery. Dismantling and cleaning should be carried out according to certain steps, otherwise it will be easily damaged. The CD-ROM drive can usually be disassembled according to the following steps.
1. Remove the backplane
Lay the bottom of the CD-ROM drive flat upward, remove the screws fixing the backplane with a Phillips screwdriver, and remove the metal backplane upward. At this time, you can see the circuit board at the bottom of the CD-ROM drive. Some CD-ROM drives have a latch on the bottom plate, and the latch is latched on the corresponding buckle of the shell (concave metal upper cover). To unload this type of CD-ROM drive bottom plate, it is necessary to push the bottom plate slightly to the back of the CD-ROM drive to make it separate from the latch, and then remove the bottom plate upward.
2. Pull out the disc tray
On the left side of the disc drive in and out button, there is a forced disc ejection hole with a diameter of 1. ~ 1.5 mm. Straighten a paper clip, insert it into the emergency disc ejection hole, and push it hard for about 2.5cm. The disc tray will pop forward, and then pull out the disc tray by hand. Some CD-ROMs don't have forced ejection holes, so you can turn on the power supply, press the in and out disk button to make the disk tray slide out, and then turn off the power supply. If there is a chuck phenomenon when the CD enters, check the lubricating oil on the slide of the CD carrier after taking out the movement. If it is too dirty or solidified, wipe it off and drop a little clock oil or high-grade butter. Of course, the chuck may also be caused by mechanical failure, so the mechanical part should be checked at this time.
3. Dismantle the front panel of the CD-ROM drive
On both sides and at the top of the front panel, there are two buckles stuck in the holes of the metal shell (concave metal upper cover), gently push the buckles inward to disengage them, and pull out the front panel forward.
4. Take out the movement
The movement (including the circuit board) of the p>SONY CDU311 optical drive can be taken out of the housing after the front panel is pulled out.
5. Cleaning the focusing lens
Turn the front of the movement upward, pull out the disc holder, and you can see the optical head assembly. The glass spherical transparent body with the size of soybean at the top is the focusing lens. Now you can clean the focusing lens with a cotton swab dipped in a little anhydrous alcohol. Before cleaning the focusing lens, you can carefully observe the surface of the focusing lens with a magnifying glass. You may see a piece of dust or fog. Wipe off the dust on the lens surface with absorbent cotton or lens paper, and after a few more rubs, you will get a clear and translucent mirror. The focusing lens is installed on the elastic body, which can exert a little force when wiping, but the displacement or deflection of the lens caused by excessive force will affect the reading disk. Do not use tweezers to avoid scratching the lens surface. Don't touch the focusing coil at the side of the focusing lens.
There has been a debate in the industry about whether it is necessary to clean the optical head and what kind of cleaning solution to use. I don't think it is necessary to use cleaning solution in general. If the dirt can't be removed by drying, consider using cleaning solution again. It is absolutely impossible to wash with water. Whether the laser head can be cleaned with alcohol is also controversial. The author thinks that it is completely possible to use high-purity anhydrous ethanol. The so-called alcohol usually refers to an ethanol solution containing water and impurities. Therefore, alcohol is really not suitable for cleaning laser heads. Anhydrous ethanol is a kind of weak organic solvent, and its purity can be divided into industrial purity, chemical purity, analytical purity and spectral purity from low to high. The higher the purity, the less water and impurities it contains. The optical head of CD-ROM drive consists of laser generator, photoelectric detector, focusing lens, laser beam splitter and servo motor. The focusing lens located under the optical disc is the most easy to get dust. In general, cleaning refers to cleaning the surface of this lens. The surface of the lens is coated with a thin film called antireflection film, and its material is magnesium fluoride. The main function of antireflection film is to reduce refraction and increase transparency. Magnesium fluoride is insoluble in ethanol, but magnesium fluoride absorbs moisture easily and deforms.
due to the analysis of pure anhydrous ethanol, the water content and impurities are already very low, and the volatility is very strong, which can dissolve organic impurities without damaging the antireflection film. Therefore, the author thinks that it is possible to clean the optical head lens with high purity anhydrous ethanol. In the actual maintenance work, this did not cause damage to the film on the lens surface. It is not advisable to clean with clean water, because magnesium fluoride is easy to deform after absorbing moisture, and there are many impurities in the water, which may damage the antireflection film and make the optical drive not work normally. Similarly, alcohol with more moisture and impurities is not suitable for cleaning laser heads.
6. Dismantle the laser head assembly
If cleaning the focusing lens can't eliminate the fault, further disassemble the laser head assembly for further processing. One side of the laser head assembly is sleeved on a cylindrical metal sliding rod, and the other side is connected with the stepping motor transmission mechanism.
the fixing point of the laser head assembly of p>SONY CDU311 CD-ROM drive is at the upper part of the CD-ROM drive. Just unscrew a screwdriver and unplug the flexible cable to remove the laser head assembly upwards. Before unplugging the flexible cable, it is suggested to draw a straight line with a pen at the interface between the cable and the socket, and mark it well, so as to judge whether it is correctly returned when restoring. Please do not disassemble the flexible cable when unplugging or inserting it. Pull and insert it lightly, which is extremely difficult to maintain after being damaged.
7. Cleaning the laser head
The laser head (laser emitting tube and photoelectric receiving tube) is installed on a small circuit board, and there are generally eight lead-out wires, which are led out by flexible cables. The laser head circuit board is mostly installed at the side of the laser head assembly. The laser emitted by the laser emitting tube passes through a right-angle splitting optical path formed by a prism and passes through a focusing lens.