Originally Posted by
Tourist in MSN
I have on rare occasion plugged an Android tablet into a charger and later found it discharged instead of charged. I suspect that one of the pins in the connection was not connected right which caused that. Since then I started using an amperage meter on my USB charging so I could see if current was actually flowing in at a rate that I wanted it to.
Im gonna say that you are right about the pin being shorted, standard USB is 4 pins (2 for power and 2 for data), if you look at a micro USB you will note 5 connections at the micro-USB end. Lets use a tablet as an example, if you plug it into a USB power source it will accept incoming power as a charge, if you have a OTG cable or device attached to the tablet it will SUPPLY power to that device (think usb stick) , the tablets know to give power by sensing the 5th pin is connected . Using a otg cable can allow you to use your tablet as a external battery for your phone or other devices if needed. I use one to supply power to a MiFi cell modem which has a pitifully small battery time as compared to my tablet. Not all devices can sense OTG however so check with the mfg or there are apps you can run to see if your device is compatable.
I think you were correct and the device went into supply power (OTG) mode.
**OTG= On The Go**