Macbook 12" - A1534 EMC 3099 - not charging battery

[PenicheFix]

Hello to everybody, I'm new on the repair and in the world of electronics, so I have a MacBook 12" A1534 from 2017, that it's slow and not charging the battery, and in the system it says "battery assistance required" it starts only with the dc adapter.
I have already the pdf file and boardview that other colleague from this community put online, but I don't now where to start. It's possible some guide lines? many thanks in advance.

Voltage: 20.03v
Amperage: 0.166 to 0.266A

[mon2]

Re: Macbook 12" - A1534 EMC 3099 - not charging battery

Are you using the official and recommend power adapter for this laptop?

If the adapter is under rated, the logic board will run slower and will be unable to charge the battery.

[PenicheFix]

Re: Macbook 12" - A1534 EMC 3099 - not charging battery

Sorry the delay, yes I'm using the original one. I also have in J6950 - PPVBAT_G3H_CONN 8.71v