Oddities with USB ports

[falcon23]

NOt sure what to think of this wierdness,but let me try to explain..

 I have a powered USB hub,I have to plug it in to get a blue power light,well if I unplug it,then plug it into  the USB,I get the BLUE powered on light,even though the power plug isnot connected.
 Another piece of weirdness along same lines..

 I can unplug my X-52 from its USB port,turn ther comp off,plug the stick back into USB and the LED's light up.

 If I have it plugged in,and shut the comp off,they go off with it and stay off,but as I say,if I unplugt the cord then plug back in with the comp off,the LED's light up..

           Sound familiar to anyone???This is a comp I built,but as far as everything working,it all works fine otherwise..dont believe I put a power supply line anywhere it shouldnt be...

                                                     Thanks,
                                                           Falcon23

[Mustaine]

everything work correctly?


don't fix what ain't broke

[NHawk]

My X45 always did the same thing on 3 different computers. So, it's normal.

My CH Fighterstick stays on even when the computer is off, so I unplug it before turning off the computer.

[Ghastly]

Many USB devices - including many hubs - are powered by the USB port on the computer.  Many motherboards continue to power USB ports even after they are "shut off", in part because many of them support the ability to start up automatically if a key on a (potentially USB) keyboard is pressed.

The power supply on a USB hub is often optional, only required to provide sufficient power to the devices that you might plug into it if you exceed a certain amount of current.

So in essence, much of what you are describing as "wierdness" is in fact not entirely unreasonable. 

I suspect the reason that the lights on USB devices like the joystick go off even though the port is still powered is that it "knows" (as long as it's powered up) that the computer has been turned off.  Unplug it, and it loses power, and when it gets power again it defaults to the lights being on.  (a reasoned guess)

<S>

[Getback]

I turn my computer off at night and can still see glowing from my bedroom. Gives me a warm and fuzzy.

[Charge]

I think that the reason why the leds turn on when stick is replugged, even if the comp is off, is that the hub should be inactive (in standby mode) and it probably is, but for some reason it wakes up from standby even if it shouldn't when its host is off.

I don't think that is all normal but on the other hand it cannot do any harm either.

The hub just powers the device all the time and the device waits to be enumerated, which it does eventually when the computer turns on.

And as was said already when the power plug is not in, the power is drawn from computer both for hub and for devices. It is not a problem unless you happen to have such devices plugged in the hub which overload the USB port in computer, causing the port to disconnect to protect its circuitry.

-C+