Power Supply Units PSUs maintenance methods

Step 1 Do not switch the machine frequently
Some of them are always shut down and restarted because of small problems. This kind of habit is very bad, which will greatly damage the computer hardware. It is best to enable hibernation if you don’t use it for a short time. Don’t drag the vibrating computer while the computer is still in use, and you can’t plug in the hardware accessories. These practices will greatly damage the computer.

Step 2 should be turned on frequently
If the computer has been idle for a long time, if it is in the summer, if the air is wet, the host is prone to short circuit caused by the tide. It is best to turn it on every day for 10 minutes a day. When it rains and thunder, be sure to turn off the computer and put all the The power plug is pulled out.

Step 3, don’t pay attention to heat dissipation
Long-term operation of the computer heat accumulation, long-term operation of the computer will slow down or crash, summer should pay attention to indoor ventilation, CPU fans to buy a better point. If it is too hot, it is best to open the cover of the case to make it easier to dissipate heat. For the problem of antifreeze, if the computer is too cold in winter, it will cause the problem of opening and not turning on.

Step 4 Pay attention to dust
Dust damage to the computer is also relatively large, usually do not open the computer case cover, when the computer is not in use, the computer host is covered with a cloth to prevent dust from entering the computer and causing malfunction.

Step 5 Try to use a three-hole socket
It is best to use a 3-hole socket to prevent static electricity from collecting on the computer. This reduces the occurrence of static electricity. If you feel an electrostatic shock on the chassis, connect the chassis to a copper wire and ground the other end.

Step 6: Turn on the peripherals and then turn on the host when booting.
The correct boot sequence is to open the peripherals and then turn on the host, such as print connection, audio, display, etc. Turn off the host first when shutting down.

Step 7: The computer cannot be loaded and unloaded during daily use.
When loading and unloading software, you should check to see if it is the software that comes with the original system. Removing the software that comes with the system can sometimes cause major problems with the use of the computer.

Step 8 prohibits magnetic objects from being placed around the display
Such as mobile phones, audio, etc., do not be placed next to the display, so as to avoid magnetic interference.

Step 9 The computer needs to carry out dust removal maintenance for half a year.
It is best to do a dust removal every few months. If you don’t know what to do, you can ask a professional maintenance person how to remove dust from the chassis to avoid damage to hardware or electric shock.

Step 10 The computer cannot be used overnight.
The computer is not used all night, which will cause the computer to accumulate too much heat, and all kinds of hardware will wear out. The long-term use will reduce the life of the computer, and the computer will also have radiation. It is not good for the body.

How do you judge that the computer power supply is broken? The motherboard does not power on the solution

1. Determine whether the computer is good or bad.

1) First, connect the host power supply (ATX), press the main switch button, if it can not be powered, then unplug the power supply to the motherboard.

2) Short-circuit the green and black wires of the power supply with tweezers, and check that the fan of the power supply does not turn. If the power supply fan turns, the power supply is good and the fault is on the host side.

3), judge the computer host switch is good or bad. Connect the ATX power cable to the motherboard, pull up the switch pin and reset pin on the motherboard, and use the tweezers to short-circuit the switch pin to trigger the power switch to see if it can be turned on. If it can, it means that the switch of the main box is broken. The switch is removed for cleaning.

4) If the short-circuit switch pin triggers the power or does not turn on, it means that the motherboard can’t trigger the boot, remove the motherboard from the chassis for maintenance.

5), remove the motherboard, first clean the dust on the board, so as not to hinder maintenance. First look at the motherboard above whether there is component burnout, drum kit, there is no burnt or broken line on the circuit board.

6), put the motherboard, plug in the CPU dummy load, plug in the power. Plug in the motherboard test card and prepare for maintenance.

2. Check the trigger circuit

When the motherboard is not powered, firstly, the specific fault circuit of the motherboard is energized by the method of forcing power. That is to say, the green line and the black line are directly short-circuited. If it can be powered up at this time, the fault is in the soft start circuit itself. If power is not available at this time, there is a serious short circuit. ATX power supply internal protection, it does not allow the voltage output by itself to the ground, so the power supply is automatically protected inside.

There may be a short circuit of the red line, a short circuit of the yellow line, a short circuit of the purple line or a short circuit of the main power supply terminal of the CPU. In the above short-circuit phenomenon, any one of the actual motherboard failures will be forced to be powered up and not powered.

Possible reasons for the short circuit of the red line are: a short circuit of the FET on the main board or a short circuit of the power manager, a short circuit of the gate circuit or an I/O short circuit, and a short circuit of the south bridge, or a short circuit of the 5V filter capacitor. Measure the 5VATX ground data or measure the value of the power supply pipe to the ground to see if it is shorted to ground. The normal ground value is about 380U. If the power supply tube is obviously measured to 0 megaohms or close to 0 megaohms, it indicates that the motherboard has ATX protection due to short circuit to ground.

For the 12V short circuit of the yellow line, it is usually the power management itself and the 12V filter capacitor short circuit. For the 12V short circuit, there may be a problem with the serial port chip.

The short circuit for the purple line may be caused by the south bridge, I/O, FET and gate circuit, as well as the purple line filter capacitor and the violet line Zener diode.

The short circuit to the CPU mains supply may be the FET, the power manager and the main supply filter capacitor. For the motherboard after P4, the CPU main power supply short circuit may also be a short circuit of the north bridge. Measure the ATX power line shorted to the pool, and then find the relevant damaged components to change along the line running circuit.

3. Check the soft boot circuit

If the power is applied forcibly, the fault is in the soft start fault itself. At this time, the soft boot circuit itself and other circuits connected with the soft boot circuit should be focused.

(1) COMS battery. Some motherboards, battery power can not be turned on, and most of the motherboard does not have a battery and does not affect the boot. The COMS battery provides a voltage of 2.6V (2.6 to 3.3V) or more under normal conditions.

(2) COMS? Practice. The COMS jumper is not correct and cannot be turned on. Generally, it is correct to jump on one or two pins, and the third pin is grounded. If you jump on the second and third pins, you will not be able to turn it on. After the mainline of argon injection is faulty, it can be turned on because the real-time crystal power supply is provided by the purple line.

(3) Measure whether the POWER switch pin has 3.3V or 5V voltage. One pin of the POWER switch pin is grounded, and one pin is powered by purple 5V. The middle part will pass some electronic components such as circuits and resistors. If there is no 5V or 3.3 voltage to the switch pin, run the circuit, look at the damage from the ATX power supply purple 5V to the components between the POWER, find the damage and then replace it.

(4) Measure the crystal oscillator next to the South Bridge chip to see if it starts to vibrate. The starting voltage is about 0.5V and about 1.6V. If not, replace the filter capacitor and the crystal element next to the crystal. There is also a way to touch the two pins of the real-time crystal by hand. After touching the motherboard, you can power up and work. After the real-time crystal is damaged, you can power up after you touch the real-time crystal oscillator, so the CPU does not work. At this time, continue to touch the two pins of the real-time crystal by hand, so that the power is turned on but the memory is not used, and then the two pins of the real-time crystal oscillator are touched, and the voltage 乂 will pass through the memory. This is a typical phenomenon of damage to the peripheral circuitry of a real-time crystal. Such a motherboard is more difficult to repair. The real-time crystal oscillator’s electric circuit is very strict. After the damage, the real-time crystal oscillator with the same colour and size will be used, and the vibrating capacitor will be replaced. Otherwise, the replacement will be unsuccessful.

 

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Connect the power switch with a Coke bottle to make the computer run more smoothly

Sometimes the computer at home is dusty and wants to clean but there are no tools. At this time, using a hair dryer is very good. One netizen gave us a way to make a simple hair dryer. Interested netizens will come and see it.

In the first step, cut the cola bottle halfway and take the upper part of the Coke bottle. Next, take out a straw, cut out the pleated section of the head, and then take out a small fan and stuff its motor into the straw.

In the second step, take out two wooden sticks on the cola bottle, sandwich the straw between the sticks, and glue them to the bottle.

In the third step, the remaining straws are folded twice and attached to the bottle as a handle.

In the fourth step, take out a charging treasure and apply glue to the bottom of the bottle.

In the fifth step, take out a switch and attach it to the handle, then solder the motor, switch and USB cable together. The hair dryer is complete.

Finally, when you need to use it, gently press the switch on the handle, the bottle mouth can blow strong wind. With it, dust will definitely be removed easily. If some netizens are interested in this hair dryer, try to do one.

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Common computer power knowledge

The originator of the power supply “AT” specification power supply
Like other early products, the AT specification was proposed by IBM. We often say that the 386 486 old machine uses this kind of power supply. This type of power supply is reloaded from the computer Pepsi network with the launch of IBM. When the PC/AT machine was proposed, the time was before the 1990s, the originator of the well-deserved computer switching power supply. This type provides +5V, – reloaded from the computer Pepsi network 5V, +12V, -12V four sets of voltage, with a hard switch. Anyone who has used an old machine such as 386 486 knows that when the power is turned on, it needs to switch a switch on the back of the chassis, and the computer will be powered by the computer. Yes, this kind of power supply can be said to be very mechanical and cannot be software switched. With the development of technology, this type of power supply has now been completely eliminated.

Milestone “ATX” power specification
In 1995, Intel introduced a new motherboard architecture – ATX, followed by the ATX specification of the power supply, and today, we are still using this system of power, but the version has changed. ATX is an abbreviation of English AT Extend and can be translated into AT extension. Compared with AT power supply, it mainly adds +3.3V and +5V Standby two outputs and one PS-ON signal, and can be softly turned off (AT needs to turn off the switch), and the output line is changed into a 20-core cable to supply power to the motherboard. .

ATX has experienced different stages, namely ATX1.01, ATX2.0, ATX2.01, ATX2.02, ATX2.03, ATX 12V (also known as ATX 2.04, ATX2.03 power supply, both of which are Basic updates, such as ATX2.2, ATX2.3.
In fact, ATX has developed to ATX 2.03. The difference between the versions is actually not big. Even in the ATX12V specification, the motherboard power supply mode of this 20Pin core is also used in the early stage.

VERSION  DIFFERENCE
ATX2.0 The air is dissipated by external ventilation, and the 1.01 uses the in-network west wind to dissipate heat.
ATX2.01  Change the +5V Standby output current from 10mA to 720mA. This change is for the Wake-on-LAN feature.
ATX2.02 A six-pin auxiliary plug has been added, and the output voltage deviation of -5V and -12V has been changed from +/-5% to +/-10%.
ATX2.03 The “Micro ATX” in the ATX2.02 version was changed to “Mini ATX” to distinguish it from another standard Micro ATX proposed by Intel.

As can be seen from the above table, the change from ATX 1.01 to ATX 2.03 is not big, because the development of the computer has not yet entered the PENTIUM4 stage. After the PENTIUM4 stage, the computing speed of the computer begins to develop rapidly, and the power consumption also follows. Go up. The ATX standard, which relies on a 20PIN core to power everything on the board, is becoming more and more stretched, so the wheel of history is rolling forward again.

Long-awaited “ATX12V” specification Strictly speaking, ATX12V is planned within the scope of ATX, but its emergence represents the development of the computer into the “modern history.” The ATX12V is also called ATX 2.04, but it has a separate name – the P4 power supply. In other words, in the face of high power PENTIME4, ATX 12V came into being. ATX 12V, as its name suggests, strengthens the current output capability of the +12VDC terminal, and has made new regulations on the current output of +12V, the peak value of the surge current, the capacity of the filter capacitor, and protection; newly added P4 power connection line; The current output capability of +5VSB; the “serial port” power supply concept also has a prototype at this time.
ATX12V specification, in fact, has also been divided into many versions, they are ATX12V1.2, ATX12V1.3, ATX12V2.0, ATX12V2.2, ATX12V 2.3, ATX12V2.31. Starting from V1.2, the ATX 12V no longer provides a -5V voltage output, because the ISA card slot interface has been withdrawn for various reasons, and the -5V output is not required.

Starting with V1.3, we have added a familiar interface, which is the SATA power port. The power supply on the market now still has this specification. From V1.3 to V2.0, the single 12V output is changed to the dual 12V output. All the way to power the CPU. The power supply interface of the motherboard is increased from 20 pins to 24 pins, which is the main line of power supply for our mainstream 24PIN core motherboard. The extra four pins, the two pins are 12V output, and the 2-pin ground wire (reinforces 12V for the motherboard). The V2.2 version follows the dual 12V design of V2.0, which increases the maximum output standard to 450W, and introduces the 8PIN power supply standard, re-planning the circuit current standard and improving the conversion efficiency.

Version V2.3 further improves the current distribution after CPU and graphics card power consumption changes. V2.31 further enhances the characteristics of balanced load, radiation protection, non-toxic energy saving, etc. It is also the highest version so far. It can be seen that starting from ATX 12V V2.2, it has been a specification we have seen in recent years, dual 12V, one CPU power supply, one peripheral device power supply. However, the release of V2.3 and V2.31 indicates that the development of power supply will lead to high conversion efficiency and green environmental protection.

The development of power supply fans has a lot of attention. The old birds who walked from DIY road will find a common problem. In recent years, the appearance of power supplies, wires, lead wires, heat dissipation methods, etc. have all undergone tremendous changes. Great changes have taken place. It must be said that with the rapid development of PC computer technology and the continuous improvement of performance, many accessories have embarked on a personalized road, adding many elements of YY, bright and colorful, if combined with a transparent or The translucent chassis will make the monotonous host shine. In the past, most of the power supply was made of galvanized sheet. In terms of wiring, the number and type of connectors specified by the manufacturer were directly soldered to the internal motherboard. The heat dissipation was mainly based on 8CM fans, and the 12CM “big windmill” was developed in the later stage. fan.

In fact, if we look at today’s eyes, the previous power supply has many drawbacks. Most of the coatings of such galvanized sheets are not very thick, and the ability to resist decay is not good. When installed, the printed fingerprints may rust in the later stage. If the weather is wet, the fan net cover and the outer casing interface will be Produced rust. Secondly, this “dead” power line mode is not conducive to users to freely increase the number of interfaces according to their own needs, and the redundant wire, not only brings trouble to the wiring, but also affects the heat dissipation of the chassis cooling air duct. effect. The 8CM fan has a large sound and low efficiency, which are some of the “hard injuries” that are now seen. In the development of this similar power supply, there have been some over-products, they have the wire wrapped in snakeskin net, have modular wiring, and 12CM silent fan, some with PWM speed, or manually set speed of the fan. The advent of these over-products has brought new ideas to the development of power supply. Slowly, these technologies have matured and manufacturers have added a beautiful appearance. The new coated shell material has become the power source we see and use now.

The wire wrapped in the high-density snakeskin net makes the wiring more convenient, making the wires that used to be like a mess become neat and tidy. Modularity gives users a greater choice of space, and it is very convenient to freely match the number of interfaces. It is worth mentioning that 12CM fans (in the past, there are similar designs, but most of them are positioned at the high end), not only bring high-efficiency heat dissipation to the power supply, but also suck the residual heat of the CPU and the power supply part of the motherboard, and blow it out of the chassis. Not to mention the finishing touch of power development, breaking the design of the internal components of the chassis, giving a whole, coordinated comfort. Now the design of the power supply can be said to give DIY players ample room to carry forward their personality.

Power parameter
Wire diameter problem
The most intuitive standard for power supply is the wire diameter. The internal current of the computer is actually very large. The output current of 12V is up to several tens of amps. There is no high-quality wire to act as a current channel, not only for hardware. Stable supply of electricity can also lead to safety risks. In general, the wire needs to have 18 AWG, that is, the cross-sectional area should be 1.00 mm2, of course, the thicker the better, the AWG value is generally on the wire insulation skin. (AWG is the abbreviation of American Wire Gauge. The single-wire conductor is based on the diameter, and the strand is determined according to the cross-sectional area.)

Power supply
The power of the power supply can be divided into: rated power, maximum power and peak power. But only the rated power and maximum power have practical significance. Rated power: The ambient temperature is between -5 and 50 degrees, the input voltage is between 180V and 264V, and the power supply can stabilize the output power for a long time. Maximum power: At normal temperature, the input voltage is between 200V and 240V. The power supply can stabilize the output power for a long time. The maximum power is generally about 15% larger than the rated power. Peak power: The maximum power that the power supply can reach in a very short time, and the time can only last between a few seconds and 30 seconds. The peak power is related to the environment and conditions of use. It is not a certain value, but the peak power can be very large, which is very easy to mislead the user and does not have any reference value. Generally speaking, the power supply XXX W mostly refers to the rated power, but there are very few behaviors that will call out the maximum power and even the peak power as a gimmick. It is especially important to polish the eyes.

What is PFC?
PFC English is called “Power Factor Correction”, which means “power factor correction”. Power factor refers to the relationship between effective power and total power consumption (apparent power), that is, the effective power divided by the total power consumption. The ratio of the amount (apparent power). Basically, the power factor can measure the degree to which power is effectively utilized. When the power factor value is larger, it represents the higher the power utilization rate. Generally speaking, the PFC circuit is a circuit that improves the efficiency of the power supply, and is divided into passive PFC and active PFC. Passive PFCs are generally classified as “inductive compensation” and “Valley Fill Circuit”. Both passive PFC circuits have a disadvantage that the power factor can only reach a maximum of 0.9, but at a lower cost. It is also easy to identify it, that is, there is often a piece of iron inside the power supply. In fact, it is not a transformer but a passive PFC.

Relatively speaking, the active PFC is usually more than 98% because it has a dedicated IC control circuit.

What is EMI?
EMI is what we call electromagnetic interference. Now the power of the power supply is getting higher and higher. The internal high current will inevitably produce strong electromagnetic interference. A good power supply needs the help of EMI filter circuit to ensure the stability of the output. A secondary EMI circuit already exists in the power supply.

5, 80PLUS standard
As a sign of conversion efficiency, 80PLUS has long been known to the public, but do you know the specific energy efficiency of the various indicators of the 80PLUS?

On each installation order, the chassis power supply is mostly in the last item. When you fully consider the configuration of the overall platform, you should consider the choice of power supply. First of all, in terms of power, try not to “eat and die”, leaving tens of watts to hundreds of watts of space to ensure stable operation of the system. Secondly, try to choose a high version of the ATX 12V specification, although the changes in each upgrade are minimal, but the progress is always progress.