The cameras often have a "type-B" USB connector (the "peripheral" side) and these aren't supposed to provide current (they are the side that normally draws current).
On addition the batteries in a camera aren't that big, you couldn't draw significant current from them without impacting the battery life.
Most cameras have historically operated in USB Device mode (which can, but is not required to, receive power from the host), not USB Host mode (which can, but is not required to, supply power to the connected device).
There is a third mode, USB OTG (on-the-go), which was created to allow for devices to act as both hosts (to power peripherals) and devices (...
I understand this is an old thread, but I’ve had similar issues and I wanted to note down my solution for anyone looking in the future.
My camera functioned fine without a CF card. Would take pictures perfectly and you’d just get a “No Card” message. When the CF cards was used, I got an Err 80 message.
From the above comments, I misdiagnosed the issue ...