Found MB has shorted data wires, just like the Sammy wall charger. See 5.11 volts dc going into tablet (get 5.36 in wall charger, but think 5.11 is not a problem). Got a short microUSB extension cable, dug out the red wire, cut it. Placed amp meter inline so I can measure amps going thru cable. With MB, I see around .45 amps, with Sammy wall charger, I see about 1.35 amps and of course lightning bolt is displayed. Tried another cheapy coiled 12 volt charger to find .45 amps flowing and displays the lightning bolt (charges the battery, though very slowly).
I prefer not returning this charger and would like to try to get it working. Does anyone else have a MediaBridge that works? Does anyone know of other things I can try to make this charge around 2 amps?