Awesome, that schematic looks correct! Its definitely not the cable, theres no current draw when the switch is off but when the switch is on the USB port draws around 300mA but doesn't charge the battery no matter how long the device is left on that way. Essentially, for now, I have to use it plugged into an external USB battery as the internal battery is nearly dead. I'm measuring a dead short on the TEMP pin which I suspect may be responsible but now that I have the schematics I can get a better idea.
