Zepto notebooks - USB power stays on when computer is off

Who else among the Zepto owners has noticed that the power to the USB ports stay on when you switch the computer off (or hibernation)? Fortunately, this only happens when the mains adaptor is supplying power and not when the PSU is disconnected.

I've noticed this feature on my 6024W but never on any other notebook which has passed through my hands.

Is it a good thing? It does mean that I can charge my MP3 player when the computer is off should I forget to do it when it is on. However, it also means that devices such as USB-powered hard disks also stay running when the computer is turned off. I also wonder what else is live when the computer is off.

On balance I would prefer the normal behaviour where "off" means off.

John

 

This was the case with my old NEC laptop...

Yes I could charge mp3 players with the USB plug.

 

Yep noticed that with the 6625WD today.

 

We've done some testing today on the 3x14/3x15W, 6x24W and 6x25WD and they all have power on the USB plugs when the PC is off or in standby.
As this is not specific to any of the models we see it as a feature of the Santa Rosa chipset.

 

Hmm, my external HDD is turned off when I shut down/hibernate/sleep the computer but I havent tested my mp3 yet (eh dont know why the **** not)

 

My Zalman NC1000 cooler stays on when I shut down the computer, it happens I forget it and it's running all night hehe
The cooler is powered through the usb for those that don't know.

 

I just tried this with a Lenovo T61 and the Santa Rosa Macbook pro. The USB power is off when the laptop is switched off. Not sure if it is bios controlled but it is not a the case that all santa rosa laptops have this.

 

I noticed this with my mobile phone and thought: "bonus" . My external hd use firewire and does correctly gets a shutdown signal when the pc shouts down, and neighter the mouse nor the keyboard stays powered when the pc shuts down, so it's the device that decides what to do.
But a thought just hit me, there are some power-saving electronic outlets which runs of a usb port, will they stay powered when they're supposed to turn off? (not that I would ever connect that kind of thing to a laptop).

 

Very very weird. It's the opposite for me on my 3415w. But I WANT my power to stay on since I have an USB loader for my mouse battery!

 

I think it is only the USB 5V power circuit which stays live. Any USB devices which have some logic circuit will switch off. An external 2.5" HDD which has a separate 5V power socket for connection to USB will normally continue to run. [I have various of these, but have not test each to see what happens.]

John

 

I have a 3,5"" or 5,5" ext hdd (buffalo 320GB) wich has external power supply (not USB) and it shuts down even If I have it plugged to the comp. Looks like this is some random stuff

 

The USBs (when the laptop is off) only provide 5V, so not everything that can charge over USB will charge. That's because some devices may want to negotiate more current, but can't - so won't charge. My mp3 player charges quite happily but my phone doesn't. Which is convenient because I don't have an AC adapter for my mp3 player, but I do for my phone.

 

Negotiate more current? That's new..

Anyway, same thing on my Amilo.

 

Yeah, see http://en.wikipedia.org/wiki/USB#Power

 

Heh... I never seen any device actually implementing a 100mA limit. So; those devices that try to negotiate actually shoot themselves in the foor I guess.