I have a Edimax USBH-007 USB Hub. I can't find out what the voltage of the
DC power cord should be (so many cords, not sure which is the right one).
Any ideas?
USB uses 5V, so while it is possible a hub could have a
step-down voltage regulator inside, this is very rare onto
the point of being almost unheard of. Try 5V, it can't be
too high and shouldn't do any damage if too low. Ideally
this should be a regulated 5V AC-DC adapter, not an
unregulated one. If it is unregulated it has the chance of
floating to a higher voltage that could damage something
unless it were very carefully mated based on it's current
capability, and even then it's better to just avoid the
typical unregulated wall-warts in favor of a regulated one.
Usually the regulated types for a hub are small switching
types, obvious because they are much lighter and thin
rectangular shape instead of more squarish shape needed to
house a (larger) transformer. Better than going by this
would be to take a multimeter and measure the voltage output
of the adapter before first plugging it into the hub.