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Laptop power supply principle and not the fault of
Notebook without power fault conditions in several ways, namely:
First, use the adapter without electricity, but the use of battery power-normal;
Second, use the adapter power-normal, but without using battery power;
Third, use the adapter and the battery can not power up.
The three failures are very common in notebook computers, in order to maintain the three failures, must have the laptop power-up process. The following simple analysis of the notebook's power-process.
When we press the power switch after the low (or high) of PWRSW # signal triggered PC87591, PC87591 and then issued a PM-PWRBTN # signals trigger the ICH, ICH back to laptop mode PC87591 three signals (Figure in step 6), and then the main power supply notebook computers to trigger the switch, such as the main power supply, CPU power supply, etc., and then follow the steps in the diagram in power. As shown.
AC IN is the adapter's power supply, Battery is the main battery power supply, the figure of the Always ON will be output as long as regular plug in the power supply, the figure of the main power supply chip (SoC is the MAX1632, there needs Note that the circuit is simply plug in the power picture will appear after the third step of the power supply, commonly known as standby power, the standby power output after the notebook is not available to some of the main power supply, laptop power supply also need to map the main The I / O PC87591 chip can drive after the standby power supply the main power supply to the laptop. The main supply-driven approach is one of a kind of notebook, there is a situation that is plug in the power system chip in the future will not produce standby power the need to drive system-chip to generate the system main power supply, the current notebook computer system main power supply both coexist.
The above principle of analyzing the power supply after the notebook, the following circuit, and in light of the failure phenomena of the previous failure analysis.
First, use the adapter without electricity, but the use of battery power-adapter power-normal or normal use, but without using battery power. Both fault detection is required for maintenance of two separate circuit protection, the figure close to the adapter and two battery box circuit, this circuit mainly consists of two separate component of insurance, MOS tube and diode. This part of the insurance is the most easily damaged, then MOS pipe, there is the diode. Encountered two separate circuits to detect the first failure of insurance, MOS tube, then is a diode, so that we can basically find faulty.
Second, use the adapter and the battery can not power up. In such failures, we are here to tell you that in accordance with the principles of analysis were used. In such fault detection process is as follows:
1, testing the main board about whether the short-circuit power supply part of the phenomenon;
2, detection of CPU power or the CPU is normal, because some machines can also cause CPU failure in power;
3, the main testing system chips power supply output is normal, if you do not need to confirm the normal output of the circuit is normal, the output circuit is mainly MOS tube and diode are normal;
4, detection system chip input power conditions, including the main power supply, etc.; detected a problem with the input circuit should carefully test the input circuit, in particular input circuits in the insurance and MOS is the most easily damaged.
In summary, the failure of laptop power failure is very common, such as voltage instability caused by prolonged use of the aging device, circuit design, current shocks can cause a power failure. If you encounter this failure to open the laptop in the case, according to the above process can be detected.
Category: Repair PC's components |
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