Motherboard not light how to repair

The motherboard does not light maintenance methods:

Example 1. A pci1600-f motherboard is not lit. First of all, visual inspection, found that the Power control IC U24 (AIC1569) surface has burned traces, welding U24, check the peripheral circuit did not see abnormal. The board returned to normal after replacing the U24. According to the user reflects this problem is more common, AIC1569 purchase is more problematic, I found from the data can be used HIP6004 directly substitute it.

Example 2. A PT-694X-A1 motherboard is not lit. The first visual inspection, no exception, after checking the CPU power supply found VCore 0V, and power switch tube gate without excitation signal. The Board power control IC U5 adopts the LM2637, which controls the power switch tube, uses the oscilloscope to check its excitation pulse output foot without waveform, and its VCC foot voltage is normal. After checking the peripheral components of the U5, we decided it was broken, and after replacing U5, the board returned to normal.

Instance 3. A gigabyte 6BXC motherboard is not lit, and is not even the power of the fan does not turn, the board has been repaired. Check the power switch tube does not penetrate, the chassis power supply ps-on end and the ground short connect to force the boot, the power supply is still not added. The 5VSB end and the power to the boot end of the voltage is normal, thereby suspecting that a certain load of the power supply may short-circuit, resulting in power protection. Compared with other BX motherboards, it was found that the resistance of +12V group was abnormally low, and the problem was estimated.

After a check found that U1 (HIP6004) 18 feet (VCC), 17 feet (lgate) to the Earth online resistance is very small, the two feet to the ground off the resistance of the offline resistor. After the replacement, this motherboard is back to normal.

Instance 4. A GVC Gbmp7va motherboard is not lit. First check the CPU power supply voltage, found both extremely low, estimated CPU power supply out of the question. Further check the power supply of the switch tube, regulator adjustment tube is not damaged, which is suspected power supply IC (AIC1567) control circuit problems. In visual inspection, it is found that the peripheral element R6 surface color anomaly, has not seen the resistance, measuring its resistance to infinity.

At one end of the R6 the AIC1567 's 22 feet are connected to the other end of the AIC1567 19 feet. From AIC1567 manufacturer's circuit diagram to see 22 feet (VCC) and 19 feet (Boost) is directly connected, so it is estimated that here R6 should be a small resistance of the decoupling resistor, from 0 to several ohms. As the saying goes: leather pants for maoku, which must have sake, R6 damage must have a reason, after check and R6 connected decoupling capacitor BC1 breakdown. The R6 and BC1 were welded back to the original position with 4.7ω resistor and 0.1μ capacitor respectively. The test machine is back to normal.

Instance 5. A AOpen AX6BC Pro motherboard is not lit, only the indicator on the test post card on the power of the instant light. It is estimated that there may be a short circuit somewhere, causing power protection. Further ask the user, the user reflects a live installation fan accidentally touched somewhere, there are sparks. In the power check on this motherboard, the power switch tube fdb7030l, Schottky diode 1n5817 breakdown damage was found. Motherboard repair in the motherboard power switch tube damage More, these switches are mostly FET, their parameters close, but many are SMD (surface mount).

To deal with this type of SMD pipe, if not, the following methods can be used: the ordinary TO220 package 60n06 with the SMD package Switch tube contrast, cut, bend the offspring. This is how I made my own "SMD" 60n06, replacing the fdb7030l, thus repairing the board. TO22O package 60n06 is commonly used in ups and other equipment, easy to buy, the price is not high.

Instance 6. A kylin bxcel PC100 motherboard is not lit. First check the CPU of each group of power supply voltage, found VTT 0V, and normal should be 1.5V. The VTT group inspection found that Q1 (H882) b, C-pin voltage is normal, e-foot without output. It is removed and the open circuit phenomenon is measured, and a fine crack is detected on the surface. With D882 substitution, the plate is repaired and the pin arrangement is paid attention to when replacing.

Instance 7. That was four years ago, there is a company a group of 30 Foyan FYI-597 VP3 motherboard has not been installed in the chassis before the test has been all no problem, but after loading the chassis has 25 is not lit. After comparing the normal motherboard, it is found that the defective motherboard's power regulator Q1 (TIP127) is damaged.

Why is it possible to damage so many motherboards? This is because the Foyan VP3 motherboard component layout is unreasonable, the previous mentioned TIP127 equipped with a radiator, just at the edge of the motherboard, loaded into the chassis easily with the chassis, and the chassis is the circuit. TIP127 Radiator (c pole) is the output of 3.3V, is not allowed to short-circuit the ground, otherwise it will burn because of overcurrent. To find out the cause of the accident, the solution to the problem is to come out-replace the appropriate chassis.

Instance 8. A MVP3 motherboard According to the user reflects the board in the WIN98 startup process, is generally in the first WIN98 screen before and after the crash. Visual inspection found that the Board CPU power supply capacity of the top of the bulge, it is estimated that these capacitor damage caused by the increase in power supply resistance caused problems. After all the damaged capacitor is removed and replaced, the plate is restored to normal by the power test. Many times found that the main board of this type of problem, are "The curse of the capacitor."

Instance 9. One ST-694XVA motherboard is not lit. Measuring the power supply voltage of each group of CPU, found that VCore only 0.5V, obviously abnormal. Check the power switch tube q13﹑q14 Normal, with the oscilloscope observation U19 (HIP6021) excitation pulse output, output waveform, U19 should be no problem. Careful observation found that the bottom of the CE35 (16v1000μ) burst, in exchange, the board returned to normal.

Example 10. A 6VIA3 motherboard is not lit. Visual inspection found that the CPU socket near the top of the capacitor burst, after the replacement of power supply still does not work, check power switch Tube Q14, Q15 breakdown, replacement.

The electric test machine, still not bright. Continue to check found R144 (2.7ω) open circuit, Power control IC U12 (SC1164) 5 feet (VCC) 12V, check the R160 (10ω) connected with the open circuit. One by one replace the above components, add electricity and try again, R160 burned again. And check the other components no exception, I decided that U12 must be broken, because there is no SC1164 had to "shutdown to be expected."

Accidentally found that there is a not fixed Intel BX Motherboard Power control IC is SC1185, can the two replace it? I immediately found the two types of IC data, a comparison found that in addition to the 6th foot difference, there is nothing different. The 6th foot of the SC1185, welded in the position of the original U12, and replaced R160 again, the result is good