15v 0.1 a but powers on and works otherwise

Purchased a switch lite that had no power, would not turn on, and had displayed the 2100-0001 error message. Found a short on M92, replaced it, threw in a fresh and known working battery sitting at 3.77 volts (32% charge) and got the system to boot. I plug in usb-c ammeter and notice it goes direct to 14.9v and .2A, then the device flickers off and then on again (boot sequence maybe?) with the same reading. After a moment or two, amps drop down to .01 and never go back up again. Left device on charger (official switch charger) for an hour or so with no joy (duh).

No other shorts on the mobo, i probed around bq chip and m92 and saw both 3.7v and 15 v on bq and 3.7 on m92. Diode tests come back normal as far as I can tell. When I unplug and plug it back in while its powered on, i see a battery message in top left but no indication its charging (cuz its not), but don’t see the no charge symbol itself. I had to replace an 0201 cap near the m92 because i floated it off into the ether by accident, however I only had .1 uf instead of the .01 it called for. Not sure if that could do it, but I have the proper ones on order now.

Any ideas? I have some BQ chips on the way, but id rather not blindly replace anything if i dont have to. Will happily provide photos or readings if anything will help, I’m a bit stuck on this one atm.

check the voltage on the test point next to battery connect with only charger connected. If you don’t see 4.25v ish there, you have a problem from BQ through 2R2 coil all the way to battery socket.

thanks for that, if you mean the pad sitting between the usb-c and battery connector, I am seeing about 50mV there. Probing the coil produces 3.2v. so the issue lies between the coil and the battery connector, or do i still look at the bq chip as the culprit?

Is the USB Port ok?
M92 failing is often caused by a Bad usb port

far as i can tell, yes. No bent pins or damage noted when using my scope. also got 15v on both sides, just no current to battery. No matter on this one as i think my over fiddling with the board damaged it beyond repair so i’ve sort of moved on at this point.

Did you replaced the BQ?

no, but again i did something stupid and now i am only getting 5v in and the vin for m92 isnt getting any power. Pretty sure i fucked this board while learning.