Switch stop charging after boot

Hi Guys,

Hope someone can help me out… trying to fix a friend switch. I stop tinkering with switches but a friend ask me to take a look

No short, charges fine when battery dead at 0.41 but when it starts to bootup and load in startuo screen m, this usually promps to fast boot but this switch just stop charging and only taking in 0.05.

Replaced m92, bq chip and fuel gauge.

Not sure what else to look at. Again it boots up and work but just not charging

Hi there,

from my side i always observed that behavior with my charger and just after boot unplug and plug it back, and then works just fine. I have no clue why it is doing that, but i have the exact same behavior without really having a real issue.

Thanks for your input. I tried it but doesnt work on my board.

Did you tried with 15V or 5V charger or both have the same behavior ?

Actually i only tried the 5v charger since thats what my amp reader is link to. Will try the 15v nintendo charger tonight.

Im thinking it has to be something where system turns on n one of the function or ic is shorted only when its on(maybe solder ball connection either joint or bad). My p13usb measure normal in diode mode but planning to replace that too when it arrives later today/tomo

I only recall one which was suffering these similar symptoms but they’re not identical to yours.

In my case it would fast charge when prompting the console to boot, but after the OS was loaded and the cable disconnected and reconnected high current did not return… I don’t remember if it was basically zero or 0.4A tbh following but certainly not what it should have been, if I remember right it threw an “unable to charge” error onscreen randomly but the usual suspects which cause this weren’t the issue. In this particular case it was (and this is becoming all to common now my end) as a result of prior over rework of the BQ, M92, P13 or USB areas (any of which) this board had other issues so it was just quicker and easier to swap the board out and I’ll transfer the SoC over to another board at a later date as I suspect line/via issues on the board as the cause.

I suppose there is a chance you have an open somewhere, so might be worth checking to see if any resistor is discoloured which might give a hint.

Hi severence, long time no chat. Thanks for the input.

Yes this does charge with 15v. V2 board, i did use pullout board to test pins in usb. Will take ur advice and poke around and see if i could find something not making contact