Hi, I have an issue with a Lite that I can’t figure out and need folk’s opinion on.
I’ll reference several photos in the post that I cannot attach to the post so here they are in a GPhotos shared album: https ://photos.app.goo.gl/o4PLBy13nPJGfyPX9
I got a Lite that worked perfectly except the USB-C port was visibly damaged and it would only charge in one charger orientation, not the other.
I did a sensible thing and swapped the port. I tested voltage drops via USB-C breakout board making sure all pins were soldered correctly, they were. The issue persisted.
Next thing upstream was M92 which I swapped.
This is where the issue got worse. I could swear that the board took charge once after the M92 swap with a proper USB-C 15v charger but again only in one orientation. When I flipped the charger port a couple of times, the board stopped charging in any orientation. It stopped powering on either.
Observations - The board still draws 0.2 amps when connected to a dummy 5v USB port, in both orientations. Nothing with a USB-C PD chargers in any charger orientation.
A 6 pin IC that looks like a FET, located close to M92 gets warm - circled red in the regular photo and seen glowing in the IR photo. I swapped it with one from a donor board and that one gets warm as well with no changes to the system so I don’t think it’s the culprit.
Another FET a little more upstream and BQ chip also get mildly warm, seen in the more blurry IR photo
I measured the voltage on the output inductor of BQ, I get ~4.2 volts there so looks like we do have VSYS rail on.
I ran out of good ideas to chase, does anyone have any opinions on what might be going on?