Can the short circuit of notebook motherboard be repaired?

Sometimes our notebook motherboard will have a short circuit fault, and some netizens will ask, in fact, it is possible, so let me tell

Can the short circuit of notebook motherboard be repaired?

Sometimes our notebook motherboard will have a short circuit fault, and some netizens will ask, in fact, it is possible, so let me tell you about the short circuit maintenance method of notebook motherboard, hoping to help you!

Maintenance method of notebook motherboard short circuit;

General maintenance idea of motherboard short circuit

Short circuit fault phenomenon: the plug-in power supply current is directly pulled to 5A, and the voltage is pulled down to 0V or close to 0V, and some motherboards will smell burnt.

Maintenance concept:

1 First, carefully observe whether there are signs of discoloration and burning in all parts of the motherboard. Generally speaking, when the components are short-circuited, due to the consumption of large current, the components will overheat, resulting in bulging appearance or discoloration and zoom. If there are burnt parts, judge the function and position of the burnt parts, and then analyze the reasons for the damage of the parts. Generally, there are two reasons: 1 the component itself is damaged; 2. The short circuit at the back stage leads to the overload of components. After the judgment, replace the good parts.

If it is still short-circuited after replacement, look down.

2. Set the current threshold of the regulated power supply to be smaller to prevent other components of the motherboard from being damaged due to excessive current, or the heating components caused by excessive current are dangerous and hot. You can first set the current of the regulated power supply at around 1A, then plug in the power supply and touch it gently with your hand to inquire about the heating element. If you find it, replace it. If no obvious element can be found, add the current and continue the query.

3 Maintenance of common short-circuit components:

Ceramic capacitor: Ceramic capacitor is a multilayer chip structure. The principle is that two charged conductors are close to each other, insulated from each other, and will contain charges. The two ends of the capacitor are not connected. The failure phenomenon of ceramic capacitor is short circuit breakdown, which is measured by multimeter. The resistance value is 0 ohms. And will not be disconnected due to the increase of current, and will always remain in a short circuit state, resulting in high temperature. It can be seen from the appearance that the contacts at both ends have traces of corrosion. The color of ceramics darkens or becomes uneven. Generally, the damage probability of the filter ceramic capacitor at the main power supply or the male terminal is relatively high. High-end and low-end MOS transistors: The function of high-end and low-end MOS transistors in the circuit is DC-DC buck, which converts the voltage of the interface card into various voltages required by the motherboard. High-end and low-end MOS transistors are generally N-channel, and only a few charge-discharge wafers will use P-channel. The phenomenon of high-end and low-end MOS damage is breakdown. Measure with a multimeter to form a passage. The common reason is that the control signal of the G pole of MOS tube is lost due to water inflow or damage of the power control core. MOS tube can not be directly powered on without power chip, otherwise it will directly lead to breakdown damage. If the MOS tube is damaged, the cause of the failure should be considered comprehensively to prevent short circuit after replacement, which will lead to the burning of components in the later stage.

Maintenance method of short circuit of additional notebook motherboard;

Fault phenomenon: My friend's motherboard is Shuoteke sl-65fv. Some time ago, he took it down and cleaned it. When he put it back, he forgot how to insert the pins of the switch and reset key. He scanned the pins with a copper key, only to see the flashing sparks, and the motherboard was silent again.

Troubleshooting: According to the phenomenon described by friends, is there something wrong with the power switch or reset button? Unplug all those plugs and short-circuit the switch pins on the motherboard with metal pieces, but nothing happened. Then remove the power supply and replace it with the author's good power supply, but the fault remains.

Remove the motherboard, memory and CPU from the chassis, and use the author's magic weapon "motherboard diagnostic card" for diagnosis. Insert the "Diagnostic Card" into the motherboard expansion kit slot, and power up the motherboard. The "Diagnostic Card" does not respond. Decided to forcibly power on the motherboard. There is a green line on the buckle side of the main power plug, some of which are gray. Short circuit with the black wire next to it, and the power supply will start.

Find the pin connected with the green line on the back of the motherboard and short it with the pin connected with the black line next to it with tweezers. At the moment when the power is turned on, the power indicator light on the "diagnostic card" flashes, which seems to be a short circuit somewhere on the motherboard, which makes the power protection device act.

However, the motherboard is so big and there are so many components. How can we know? I thought that since there was a short circuit, its upper level should be hot, so I kept connecting the two pins quickly. After dozens of times, I began to touch the components near the power plug on the motherboard and found that the CET CEB6030L lamp was hot. It seems that it is either broken or the nearby components are short-circuited. Take it off with a soldering iron and measure it with a multimeter. It is found to be good. There are two lamps similar to CET CEB6030L near the CPU socket, which seems to regulate the power supply of the lamps to the CPU.

Down the line, the author found a small integrated block HIP60 18BCB. If it is burned short, CET CEB6030L is bound to heat up. The author removed the integrated block with soldering iron and tin sucker. After the main board was electrified, it was found that the main board could be electrified, and CET CEB6030L was not hot. It seems that the integrated block HIP60 18BCB is really broken.

It took 15 yuan to buy a scrap board of sl-65fv. Remove HIP60 18BCB from the waste board, weld it on a friend's motherboard, connect the load, and power on the motherboard. At this time, the power indicator on the "Diagnostic Card" shows that everything is normal. The measured voltage is normal. After the CPU and memory are installed, press the power switch excitedly, and the number of the digital tube on the "diagnosis card" begins to jump, from "C 1" to "03" to "05", and then returns to "C 1" to start the cycle. It seems that there is more than one motherboard failure.

I opened the instruction of the "Diagnostic Card", which said, "If the manufacturing test 1 5 is repeated continuously, the 8042 control state can be obtained". I don't seem to get the "8042 control state", but I found the information about "8042 control state" on the Internet, but the general idea is that it is related to input and output, which is very vague. The IC chip controlling input and output on the motherboard is Winbond W83977EF-AW.

The motherboard has been powered on for a long time, and it is not hot at all. Will such a large integrated block be broken? I'm not sure, but I decided to try another one. There is nothing I can do to remove this integrated block with an electric soldering iron and a tin sucker. Remove the wafer on the 850 hot air welding table, and then weld the wafer on the scrap board.

Reinstall the CPU and memory, then connect the keyboard and monitor, turn on the power switch, successfully enter Win98 after booting, and the execution program is normal.