|You normally only hear the USB connection connect or disconnect sound when you plug in or unplug a USB device. If you hear it at other times....|
- you may have a loose USB connection - try plugging into other USB ports, and/or making sure the USB plug on the end of the cord is not bent out of shape, and/or making sure the plastic blocking plug is still there and secure in the plug and the port. If the USB port is connected to a front port on the case, or is a port in a plate in a slot space at the back of the case, make sure the wiring connector(s) that connects it to the mboard is/are not loose on the mboard header pins.
- the USB cord may have broken wires inside it - if the wire insulation is still intact, if the wire ends are still touching the device will still work but that wire's connection is iffy, and you may hear the USB connection or disconnection sound at random.
- ports directly connected to the mboard, or ports in a USB controller card in a slot, or ports in adapter plates at the end of slots that connect to two, or more, individual ports on USB headers on the mboard, are the most reliable ports to use.
- some devices do not work properly when connected to a USB hub, that is, a hub that is two or more ports connected to one USB port directly connected to the mboard, even if it is a "powered" hub that has an extra power supply so all the ports can be supplied with the standard 500ma even if all ports have something in them. If that kind of hub is not "powered" it shares the 500ma the one directly connected port provides with all the ports in the hub, and that can cause problems when more than one device is connected to the hub. Most multiple USB ports higher up on a case front, USB ports on a keyboard, and USB ports on a printer or all in one are this type of hub.
If another USB connected device that is more sophisticated is connected to such a hub, you may have problems with simpler devices plugged into same hub when more than one device is connected to it.
- some case wiring to USB ports on the front of a case, usually the two lower down on the case, that is wired to two port connections on a USB mboard header, is inadequate, and some devices will not work properly plugged into those ports.
e.g. such front ports I have on one case work fine with mice and keyboards (USB 1.x devices) but will not work properly with USB flash drives, printers, scanners, or an iPod Shuffle.