I tried looking through the schematic, but I couldn't figure out which connection was the USB port.
When you plug in a Yun through the mini USB port, it get's 5v from the computer (or USB charger). Does that 5v line connect to the 5v power line? Is there anything in between, any chips or regulators?
I know a "regular" Arduino has a regulated 5v line, so you can't pump too much current through it. What's the current limit for the 5v line on the Yun?