How to repair laptop not charging problem

Laptop Battery not charging it’s one of the famous problems in laptop, which have a large share in the faults. So today I will talk to you about tracking the failure of charging in some cases:

Measuring the voltage on the charger

First make sure to measure the charging socket of the charger outlet, The picture below shows you how to measure the voltage output,

Note: Output voltage for the AC Adapter in picture may differ from the one you are used.

The AC adapter with 3- pins output such as the Dell charger or HP charger needs a measurement that is different from the other AC adapter with 2-pin output. You need to measure the ID needle voltage, without this voltage the charger does not charge. The laptop is only power on but without charge the battery. The voltage on the needle is 5 volts in most case. Then measure the voltage 19V or 18V according to the charger. If the voltage is not correct, replace the AC adapter.

If the power-on indicator does not turn on, check the power cord of the AC adapter for correct continuity and installation.

Measuring the voltage on the power-jack

Second we must measure the voltage on the power jack, to make sure of the power jack pins is ok.

Measure the voltage on the COIL after power jack and check the SMD capacitor

The 19V or 18V voltage regulation circuit consists as follows:

Measuring the voltage on the VALW MAIN LINE

From “VALW MAIN LINE” Battery IC and dc/dc power supply IC and this main VALW line also distributed adapterVoltage to every N channel Source ,before they got enable trigger to produced 3 and 5V_ALW

The voltage goes from the power jack through fuse, SMD coil, SMD diode and then MOSFET switch power.

The MOSFET Gate takes the pulse from the charging IC and output the 19 volts to Drain leg, which feed the primary and secondary MOSFTEs, until the 11volts reach the first leg of the charging socket.

The laptop does not charge the battery

Check 19 volt above the power jack, 19 voltage tracking up to the top and bottom charging terminals, Checking all the fuses found in the 19volts line, Checking for volts on the battery Socket.

The laptop does not work from the charger and works from the battery

Check Charging MOSFET and IC for probably there is a burn, also check the

The laptop turn off when plugin the charger

Check the all MOSFETs on the “VALW MAIN LINE” there is a burn MOSFET.

The laptop turn off when plugin the battery

Check the primary and secondary MOSFETs, there is a burn MOSFET.

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