I had this issue as well. Diode had failed short. I removed it and now can charge fine. Was either a very poor design to “protect” against reverse polarity (still “kills” the tablet), or it was a zener/tvs diode and it “saved” the tablet from a bad charger putting out a voltage a good ways higher than 5v. I have a MMBZ5V6ALT1G that I have laying around that I’ll try to cobble in there (SOT-23, should be able to get at least one of the internal diodes soldered down). The 6V2 part would probably be better to use since the 5V6 can start breaking down as low as 5.3v. Maybe this is what the original part was and this is why it fails? I could just leave it off, but I feel like I’d be one step away from a bad charger taking the tablet out for good.