blu
Wants the largest console games publisher to avoid Nintendo's platforms.
The voltage cannot vary - it is constant as per the USB standard. It's the amperage you're thinking of. Now, every USB device reports its own amperage needs, as part of the handshake protocol*. Your USB pendrive could just as well be mis-reporting its own power needs.I can't find a powered USB hub at the moment, but I can confirm my USB drive's LED very faintly flashes when plugged into the Wii U and if I plug it into my computer the LED flashes normally.
Considering other people are having issues I'm thinking the firmware changed the power levels that the Wii U's USB ports put out or it tried to detect what voltage needs to be put out and wrongly assumes a lower one for some hard drives / thumb drives.
* Which is what allows the USB managers in some OSes to inform you when you overload a USB bus.