Notebook motherboard short-circuit Reason

Notebook motherboard short-circuit reason analysis:

Notebook motherboard short-circuit is only two possible, on the one hand, the motherboard itself is not good insulation, on the other hand may be the motherboard has foreign metal pieces (such as screws) lead to short circuit.

Due to the limited volume, General notebook motherboards are stacked together by Multi-layer circuit board made, if the motherboard in the production process is not good, or occasionally caused by bad insulation, in the case of large current, very likely to lead to short-circuit. Alternatively, a possible accident is that a metal drop on the motherboard causes the two devices that have been separated from the insulation to lap up and thus short-circuit.

After a short circuit may have two kinds of performance, one is obviously has the scorch appearance, this kind of situation is easy to repair. The other is short-circuit current is not too large, the appearance may not be seen, more difficult to confirm the fault.

Laptop motherboard Short-circuit Solution:

General maintenance idea of motherboard short circuit

Short-circuit fault phenomenon: Plug the current direct pull to 5 A, voltage down to 0V or near 0V, the motherboard will have a burning odor

Maintenance Ideas:

1 First, carefully observe the parts of the motherboard whether there is a discoloration of the burnt paste traces. In general, each component in the short circuit, due to the consumption of large current, will lead to excessive heating components and appearance of bulging or color change zoom. If there is a burnt paste element, judge the role and position of the burnt paste element, then analyze the cause of the component damage. There are generally two reasons: 1 component itself is damaged, 2 back-level short-circuit cause component load too large. After good judgment, replace the good components.

If replaced, still short-circuit, look down.

2 will be regulated power supply of the current threshold set smaller, prevent the current too large to cause other components of the motherboard damage, or the current too large components of heat generation risk (hot). You can set the current voltage-stabilized power supply to 1A or so, and then plug in the power, gently touch with the hand to find the heating elements, such as find, replacement, if you can not find the obvious components, increase current, continue to find.

3 maintenance of common short-circuit components:

Ceramic capacitance: Ceramic capacitor is multilayer chip structure, the principle is that two charged conductor close to each other, insulation, will accommodate the charge. And the two ends of the capacitor are not able to pass. ceramic Capacitor damage failure phenomenon is short-circuit breakdown, using a multimeter to measure, resistance 0 ohms. and will not open because of the rise in the current, will remain in short circuit, and will produce high temperature. Appearance can be seen at the end of the contact traces of corrosion. The ceramic color becomes darker or becomes uneven. Generally in the main power supply or the public side of the filter ceramic capacitor damage probability is relatively high. High-low End MOS tube: high-low-end MOS tube in the circuit is the role of DC-AC step-down, the adapter voltage conversion to the motherboard required by the various circuit voltage. High-Low-End MOS tube is generally n-channel (only a small part of the charge and discharge chip will use P channel), the High and low end MOS damage is the breakdown of the phenomenon. The use of multimeter to measure the formation of the pathway. The common reason is due to the power supply control core water or damage, resulting in MOS tube g very lost control signal (MOS tube can not be in the absence of power supply chip directly power, or directly lead to breakdown damage). If you encounter the failure of MOS tube damage, to take into account the cause of failure, to prevent the replacement is still short, resulting in the burning of the rear level components.

Attach notebook motherboard short-circuit repair method:

Symptom: The friend's motherboard is the Shuo Tai Gram sl-65fv, some time ago he took down the motherboard to sweep, and so on when you forget the switch and reset button that row of pins is inserted, he used the copper key in the row of pins swept a moment, saw sparks Flash, the motherboard has no movement.

Troubleshooting: According to a friend description of the phenomenon analysis should be a power switch or reset key problem? Pull those plugs down and then use the metal to short-circuit the motherboard on the switch pins, or no movement. And then remove the power to replace the author's good power, but the fault is still.

Removed the motherboard from the chassis, remove the memory and CPU, using the author's Magic "Motherboard diagnostics card" to diagnose. The diagnostics card is plugged into the motherboard expansion slot to power the motherboard and there is no response on the diagnostics card. Decide on the motherboard to force the power on the main plug on the block button on the side of the Green Line is gray, and it will be with the next black line short connect the power is started.

Find the Green line attached to the back of the motherboard with tweezers to root cuttings it and the root cuttings needle next to the black thread. At the instant of the power supply, the power indicator on the diagnostics card flashed, which appears to be a short circuit on the motherboard to enable the Power Saver to act.

But the motherboard is so big, so many components and how to check up? I think since there is a short circuit exists, then it should be on the first level of fever, and constantly quickly connect the two root cuttings needle, dozens of times after the start touch the motherboard near the power plug components, found that CET ceb6030l this pipe hot heat, It looks like either it's broken or it's a short circuit in the vicinity, with a soldering iron to remove it and use a multimeter to find it is good. such as the CET ceb6030l pipe in a total of two near the CPU socket, it seems that the composition of the tube to the CPU power to adjust the role.

Follow the line down the author has found HIP6018BCB this small integration block, if it burns short circuit so cet ceb6030l bound to fever. The author uses the iron and the tin-absorbing device to scrap the Dickens the integrated block to be removed, and then to the motherboard power when found that the motherboard can be on the power, CET ceb6030l also not hot, it seems that HIP6018BCB this integrated block really bad.

It cost 15 yuan to buy a piece of sl-65fv of the Shuo Tai gram. Remove the HIP6018BCB on the scrap board to weld the motherboard to a friend, connect the load, and then power on the motherboard, and the power led on the diagnostic card shows that everything is OK. Normal voltage measurement, loaded with the CPU and memory with an excited mood press the power switch, "diagnostic card" on the number of digital tube began to beat, from "C1" went to "03" and then to "05" and Back to "C1" from this began to cycle, it seems that the motherboard has more than one fault.

Turned on the "diagnostic card" instructions, which said "if you repeat the manufacturing test 1 to 5, you can get 8042 control status." It seems that it did not get "8042 control state", and the Internet to find "8042 control status" Aspects of the information, but said is very vague, the effect is related to the input and output. The IC chip that controls the input and output on the motherboard is Winbond W83977ef-aw.

The motherboard is energized for a long time and it is not hot at all. The author is a bit uncertain, but decided to try another. Disassemble this integration block rely on the author's soldering iron and tin-absorbing device has been powerless, in the 850 hot air welding platform will be removed, and then the chip on the scrap plate welding up.

Again the CPU and memory are installed, and then connected to the keyboard, monitor, turn on the power switch, start smoothly into the Win98, running the program is also normal.