In some cases our motherboard does not light up, what is the reason? How should this be repaired? The following by me to you a simple introduction to the motherboard does not light up the repair method! I hope to help you oh!
Motherboard Introduction:
Motherboard (English: Motherboard, Mainboard, referred to as Mobo), also known as the motherboard, system board, logic board, motherboard, motherboard, motherboard, and so on, is the composition of a complex electronic system, such as the center of the electronic computer or the main circuit board.
A typical motherboard provides a series of junctions for devices such as processors, graphics cards, sound cards, hard disks, memory, external devices, and so on. They are usually plugged directly into the relevant slots or connected by wires. The most important component on a motherboard is the chipset. Chipsets are usually composed of a Northbridge and a Southbridge, and some are designed with a single chip to enhance their performance. These chipsets provide a common platform for the motherboard to connect different devices and control the communication of different devices. It also includes support for different expansion slots, such as processor, PCI, ISA, AGP, and PCI Express. chipsets also provide additional features for the motherboard, such as integrated graphics, and integrated sound cards (also known as built-in graphics and built-in sound cards). Some high-priced motherboards also integrate infrared communication technology, Bluetooth, and 802.11 (Wi-Fi).
Maintenance methods for motherboard lights that do not come on:
Example 1: A PCI1600-F motherboard does not come on. First of all, visual inspection, found that the power control IC U24 (AIC1569) surface burn marks, welded U24, check the peripheral circuitry is not abnormal. Replacement of U24 after the board back to normal. According to the user to reflect the board this problem is more common, the purchase of AIC1569 is more problematic, I found from the data can be used HIP6004 directly instead of it.
Example 2. A PT-694X-A1 motherboard does not light. First of all, the visual inspection, no abnormality, after checking the power supply to the CPU found Vcore 0V, and power switching tube gate no incentive signal. The board power control IC U5 used LM2637, by which it controls the power switching tube, with an oscilloscope to check its incentive pulse output foot no waveform, and its Vcc foot voltage is normal. After checking the peripheral components of the U5 no problem to determine that it is bad, replace the U5, the board back to normal.
Example 3, a GIGABYTE 6BXC motherboard does not light, and even the power supply fan does not turn, the board has been repaired. Check the power switching tube is not broken, the PS-ON end of the chassis power supply and ground shorted to force the boot, the power is still not added. Measure the 5VSB terminal and power supply start-up terminal (POWER ON) voltage is normal, thus suspecting that the power supply of a load may be short-circuited, resulting in power protection. In comparison with other BX motherboards, the resistance value of the +12V group was found to be abnormally low, and the problem was estimated to arise from this.
After some checking, I found that U1 (HIP6004) pin 18 (VCC), pin 17 (LGATE) on-line resistance to ground is very small, it will be soldered down, measured these two pins on the ground offline resistance is also the same. After replacement, the motherboard is back to normal.
Example 4: A GVC GBMP7VA motherboard does not light. First check the CPU power supply voltage, found to be extremely low, it is estimated that the CPU power supply problems. Further inspection of these power switching tube, voltage regulator adjustment tube is not damaged, thus suspecting that the power supply IC (AIC1567) control circuit has a problem. In the visual inspection of the peripheral components found on the surface of the R6 color is abnormal, has been seen resistance, measured its resistance to infinity.
One end of R6 is connected to the AIC1567's 22 feet, and the other end is connected to the AIC1567's 19 feet. From the AIC1567 manufacturer to provide circuit diagrams on the 22 feet (Vcc) and 19 feet (Boost) is directly connected, so it is estimated that here R6 should be a small value of decoupling resistance, probably from 0 to a few ohms. As the saying goes: leather pants for wool pants, which must be the cause of the damage to R6 must have a reason, after checking the decoupling capacitor connected to R6 BC1 breakdown. R6 and BC1 were 4.7 resistance, 0.1 capacitor welded back to its original position. The test machine is back to normal.
Example 5: An Aopen AX6BC Pro motherboard does not light up, but only detects the indicator on the POST card in the moment of power-up. It is estimated that there may be a short circuit somewhere, resulting in power protection. Further questioning of the user, the user reflected that when installing the fan with power had inadvertently touched a certain place, there are sparks appear. In the power supply inspection of this motherboard found that the power switching tube FDB7030L, Schottky diode 1N5817 breakdown damage. In the motherboard repair in the motherboard power switching tube damage more, these switching tubes are mostly field effect tube, their parameters close, but more SMD (surface mount).
Against such SMD tubes, if you can not buy, the following method can be used as a simple replacement: ordinary TO220 package 60N06 SMD package with the switching tube contrast, cutting, bending and substitution. This is how I made our own SMD 60N06, replaced the FDB7030L, thus repairing the board in one fell swoop. 60N06 TO22O package is commonly used in UPS and other equipment, easy to buy, the price is not high.
Example 6: A Kirin BXCEL PC100 motherboard does not light. First of all, check the CPU power supply voltage, found that the VTT is 0V, while the normal should be 1.5V. VTT group check found that Q1 (H882) of the B, C feet of the voltage is normal, E feet no output. Will be removed, measured open-circuit phenomenon, look at its surface has a fine crack. With the D882 substitute, the board can be repaired, replace the attention of the pin arrangement.
Example 7. It was four years ago, there is a company a batch of 30 FYI-597 VP3 motherboards in the chassis has not been loaded one by one before the inspection are not a problem, but loaded into the chassis after 25 pieces of non-light. After comparing the normal motherboards, we found that the power regulator Q1 (TIP127) of the problematic motherboards have been damaged.
Why can so many motherboards be damaged? This is because the layout of the components of the Fuyang VP3 motherboard is not reasonable, the aforementioned TIP127 equipped with a heatsink, just located on the edge of the motherboard, installed in the chassis is very easy to touch with the chassis, and the chassis is the ground of the circuitry. TIP127's heatsink (C-pole) that is, the output of 3.3V, is not allowed to short to ground, or it will be burned because of the overcurrent. Identified the cause of the accident, the complete solution to the problem came out? Replace the appropriate chassis.
Example 8, a STARK MVP3 motherboard, according to the user to reflect the board in the WIN98 startup process crash, usually just before and after the appearance of WIN98 screen crash. Visual inspection found that the board CPU power supply capacitors have bulged at the top, it is estimated that these capacitors may be damaged resulting in increased internal resistance of the power supply and triggered the problem. Will all the damaged capacitors removed and replaced after a good, the board by powering up the test returned to normal. Many times found asus tektronix motherboard such problems, are? The main reason for this is that it is not a good idea to use the same technology as the original.
Example 9, a ST-694XVA motherboard does not light. Measuring the CPU power supply voltage of each group, found that Vcore only 0.5V, obviously abnormal. Check the power switching tube Q13, Q14 normal, with an oscilloscope to observe U19 (HIP6021) excitation pulse output, there is an output waveform, U19 should be no problem. Carefully observe the CE35 (16V1000?) bottom burst, change, the board back to normal.
Example 10. A Chengqi 6VIA3 motherboard does not light. Visual inspection found near the CPU socket capacitors are burst at the top, replace the power supply is still not working, check the power switching tube Q14, Q15 breakdown, replacement.
Power on the test machine, or not bright. Continue to check the discovery of R144 (2.7?) open circuit, power control IC U12 (SC1164) 5 feet (Vcc) no 12V, check with the connected R160 (10?) open circuit. One by one to replace the above components, power and try again, R160 burned out again. And check the other components are not abnormal, I decided that U12 must be bad, because there is no SC1164 on hand had to? The first time I saw this, I had to stop working and wait for the material to be available.
By chance, I found myself with a piece of unrepaired Intel BX motherboard power control IC is SC1185, both can be replaced? I immediately looked for information on these two ICs, and after some comparison found that the two are different except for the 6th pin, nothing else is different. The SC1185 pin 6 suspension, soldered in the original U12 position, and again replaced R160, the results are good