Xiaomi 6X mobile phone will not be charged for a few seconds

It is found that there is a resistance between the capacitors connected at both ends of the charging and buck inductor. Replace a rich inductor, start the test, and everything is normal.

Machine model: Xiaomi 6X

Fault phenomenon: After a few seconds of normal charging, there is no charging sign.

Xiaomi 6X mobile phone doesn’t charge for a few seconds. Troubleshooting Figure 1

Fault analysis:

Xiaomi 6X mobile phone has a charging sign indicating that the charging ic has worked normally and then disappeared. First, check whether the working conditions of the charging ic are disturbed.

Maintenance process:

Last time, it was said that it happened after charging with a brand-name charger, so I suspected that the charging ic was broken and there was no chip replacement. Firstly, the step-down circuit is measured, and it is found that the resistance value is generated between the capacitors connected at both ends of the charging step-down inductor.

Xiaomi 6X mobile phone doesn’t charge for a few seconds. Troubleshooting Figure 2

It is the first time to remove the inductor and measure its resistance at both ends, indicating that the high voltage burned out the inductor and produced internal resistance.