Will lsusb and lspci list devices for which the system has no drivers?

lsusb and lspci scan the buses at a low level, and do not require drivers in order for the devices to be found beyond those for the buses themselves.

As Ignacio says, lsusb and lspci do not need drivers - if something is connected they will show it, though they may only show a few numbers without any descriptive text if the connected device is not recognised - that is if the id number of the connected device is not in the database of values.

If there is not even an unlabelled device in the output, then it is likely your webcam is dead, or possible the USB port is dead. I would try the webcam in another computer, and try another device in the USB port. Does the webcam have any switch on it?

Also note that lspci will show USB controllers on the PCI bus, but it will not list any devices connected to those controllers, only lsusb will show that.

Try "lshw" as superuser. It gives a detailed list of all hardware, your camera and details about it should be listed in there.