I have a switch motherboard from a V2 that recently removed the charging port from. AT that time, it booted to the OS fine. I took it back out to put a new port on, seemingly went really well. But then no longer booted. I realized I messed up the FPC pins on the LCD, so I replaced that as well. Then when I put it back together it no longer responds to power button press. Battery is charged, no shorts on BQ, M92 or P13 USB. Was previously working. I think maybe the alligator clips I was using might have broken the MAX17050 chip. I think I know the answer but this likely is the culprit?
Really nice picture quality. Can you attach pictures of the stuff you repaired and the board just to get a 2nd pair of eyes on it.
I really only did the port removal and replaced the LCD. The LCD FPC might have some legs that look funny but I checked each them all to make sure they were connected.
There also is this area near the VGA chip (I think its the VGA chip). The top layer was scuffed but the chip looks ok
to answer your initial question, yeah you knew, the fuel gauge is bad.
The ENXX IC doesn’t look too hot either but it may just be the top coating and the die may be fine.
2 Likes
I assume that ENFG chip is the one you’re talking about? yeah Im a bit concerned but looking at it sideways it didnt look cracked or anything. I guess I could order one of those too 
Just to chime in, I have a similar situation. Switch booted, charged, worked fine but at time would turn off. I found a faulty BQ and replaced it now it wont boot. Turns out the battery although holding voltage is faulty. I didn’t notice right away but it was a bit puffed up, just so slightly that the only way I did notice is because the sticker padding around the battery looked flat compared to others. Tried a different battery and it booted up.
Also you are right in your assumption ENXX is the ENFG in your case.
Yeah the batteries I have are good and around 4V so fully charged! Im hoping the ENXX chip is okay. Will replace the Fuel gauge and go from there… i suspect my helping hand arms are damaging my boards. I didn’t notice till now 
ENxx Is 3.3V regularor, most of the time overlook by repair tech.