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Dongguan Jiuqi Industrial Co., Ltd.
Contact: Mr.liang
Mobile: +86-13122876672
Tel: 0769-81818179
Fax: 0769-81806179
Address: Kongwu District, Guxia, Shipai town, Dongguan city
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E-mail:haulwee@vip.163.com
Laptop computer field effect tube damaged and unable to use the power adapter
| Laptop computer field effect tube damaged and unable to use the power adapter |
| Laptop computer field effect tube damaged and unable to use the power adapter The fault phenomenon A laptop can start up and run normally with a battery, but can't do so when powered by an adapter. Fault judgment There are three main reasons for this kind of failure. The first one is the failure of the power adapter itself, which cannot convert the mains power into a power supply of more than ten volts. Therefore, when dealing with this kind of fault, the power adapter fault should be eliminated first, not blindly disassembling and testing, so as to avoid wasting time and energy. The second aspect is mainly the failure of the power interface circuit of the notebook computer, which leads to the failure of the power adapter to input the protection and isolation circuit normally, resulting in the failure to start up normally when the power adapter is used. The last aspect is the damage of the field effect tube or related electronic components in the protective isolation circuit, which causes the power supply of the power adapter to enter the protective isolation circuit, but it cannot be normally sent out to supply power to the standby circuit, resulting in failure of startup. troubleshooting According to the above fault analysis, the fault laptop was tested, and it was finally found that the field-effect tube which played the role of power supply isolation was damaged, which caused the power adapter power supply could not be normally input. After the field-effect tube was replaced, the fault was removed. The laptop cannot be started due to a broken standby chip The fault phenomenon A laptop can not be started up, the use time is 3 years, failure before no water, impact and other conditions. Fault judgment Laptop computer can not start the fault, is a more common fault phenomenon, maintenance of such a fault should be in accordance with the power supply, clock signal, reset signal sequence detection. When testing the power supply, firstly check whether the power supply of the power adapter and battery of the laptop is normal. If the external power supply of the laptop is normal, the machine can be dismantled for testing. The power adapter supplies power from the laptop's power interface into the protective isolation circuit and then supplies power to the standby circuit when the laptop is not turned on. Therefore, it is necessary to first check whether there is 3.3 or SV standby voltage on the power switch of the host machine after dismantling. When there is no 3.3 or SV standby voltage on the host power switch, the standby voltage output by the standby chip in the standby circuit should be checked first. If the standby voltage output by the standby chip is abnormal, it is necessary to check whether the input voltage of the standby chip is normal. If the input voltage of the standby chip is normal, the standby chip and related electronic components should be inspected for possible faults. If the input voltage of standby chip is abnormal, it is necessary to check whether the protective isolation circuit, battery interface circuit or power adapter interface circuit and other superior power supply circuits are normal. troubleshooting After testing, standby chip has power input, but no power output. From this, it can be judged that there is basically no problem with the protective isolation circuit, battery interface circuit, power adapter interface circuit and other superior power supply circuits. The problem lies in the standby chip itself. After replacing the standby chip, the fault can be eliminated. |
| | release time：2019.09.23 Source： |
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Contact: Mr.liangTel:+86-13122876672Tel:0769-81818179Fax:0769-81806179 E-mail:haulwee@vip.163.com
Address: Kongwu District, Guxia, Shipai town, Dongguan city, China Zipcose:523,339
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