LAPTOP HP 15-DY2059LA / i3-12gen has stability problems in vccpu coils, BUZZING SOUND. ¿Coil whine?

[valente222]

Hello friends, I just received this equipment, it has a strange hum on the board. The computer works fine, outputs an image and starts Windows. But the problem is when charging the battery, a constant loop to charge. In short, it never charges the battery. When the charger is connected, the stability of the CPU is stressed and it seems that the coils make that electrical sound louder. This board is modern and I don't have a schematic. I have checked with a microscope and the pcb is completely new. Has anyone had this happen to them before? defect in driver ic?

[mcplslg123]

So the mb works fine with adapter alone or with battery also? Does it works when both battery +adapter is connected?

You should focus on charging IC as well as dc-in mosfets+discharge mosfet.

[valente222]

So the mb works fine with adapter alone or with battery also? Does it works when both battery +adapter is connected?

You should focus on charging IC as well as dc-in mosfets+discharge mosfet.

Mr. mcplslg123 good day, about the equipment only works on the battery. If I want it to work with the adapter I must take out the battery. Also be tested with other voltage adapters. Thinking they were the input mosfets before the main sensing resistor everything apparently ok. The hums are coming from the VCC CPU coils. Could it be that B+ voltages are affecting this sector? With the oscilloscope, it detects noise.

[valente222]

Reviewing personally I have tested with 3 adapters, the first two adapters were original they worked horrible send noise, just measure VCC of the BQ728H charging ic with the probe. "Reference image."
And to top it all off, the noise disappears when connecting the last and third adapter which is NOT ORIGINAL. hahaha it's funny. I will continue to analyze this IC LOAD. Probable manufacturing defect?