Same thing happened to me yesterday, plug in the USB lead and I get the orange light for a while, plug the wall charger in, nothing.

After some messing around with the multimeter, I'd say your problem is the same as mine (and 2000 other people) - broken USB / Charging port. In my case it was a dry solder joint on one side that allowed a very tiny (almost imperceptible) amount of movement to occur.

The solution for me is to go to the cell phone market and finally visit one of those people that annoy you with "You want cell phone repair sir?" - they all have heat guns, I'm sure one of them can fix it :-)