With USB power delivery, you can get 9V, 12V or higher over USB. Usually the device requests higher voltage from a PD charger, but it’s not impossible for a modern device to be able to cope with just having 12V shoved into it.
That’s probably only true for USB power supplies - a USB adapter isn’t set up to do anything with voltage and probably just passes the positive and negative pins through.
The VGA adapter feeding power back through USB in the first place, yeah, that’s not supposed to happen.
Put it this way, either the standard on the other end of the adapter specifies 5V, or the adapter doesn’t just pass it through, or the adapter is broken!
With USB power delivery, you can get 9V, 12V or higher over USB. Usually the device requests higher voltage from a PD charger, but it’s not impossible for a modern device to be able to cope with just having 12V shoved into it.
The USB device would have been made wrong if it just shoved 12V down the power lines without negotiating it.
That’s probably only true for USB power supplies - a USB adapter isn’t set up to do anything with voltage and probably just passes the positive and negative pins through.
The VGA adapter feeding power back through USB in the first place, yeah, that’s not supposed to happen.
Put it this way, either the standard on the other end of the adapter specifies 5V, or the adapter doesn’t just pass it through, or the adapter is broken!