There was some chat a few pages back about the Zen Dac 3 not powering off on computer shutdown when using USB power.
I went through the same thing with a different USB powered DAC and did some reading and discovered something that I didn't previously know was even a thing, it might be useful to somebody here.
On many/most computers the USB ports will still be powered even when the computer is shut down. That probably isn't a big deal but of course the DAC will light up and the battery of a lap top will be draining if left like that for an extended period of time.
The option to have power at the USB ports can be controlled, at least in some circumstances and some ports.
My scenario is a HP Z Book but the same likely applies to many others with different ways of achieving it.
I did a Google search about turning off USB power at shut down and found a raft of information, most of which was not applicable to my lap top. All sorts of settings within the Device Manager - Universal Serial Bus Controllers and Control Panel - Power Options and so on which ended up in dead ends with comments about settings that were not even there or didn't do anything if they were there.
However, I ended up with success in the BIOS (Basic Input Output System) setting, at least for the "Legacy" USB-A ports but not the USB-C ports, I could work with that.
There was an option to turn off USB power from the two "Legacy" USB ports (the USB-A ports) in the BIOS, literally uncheck a box and reboot. I could not find options for the USB-C ports.
The management options within the BIOS seem to differ wildly between manufacturers so I can't offer specifics but if you are stuck with a device that is constantly powered from the USB there may be a way to manage the USB power available at the ports after shut down. It will probably take some research to get to the BIOS and then to the right settings in the BIOS but there may be a relatively straightforward way to achieve unpowered USB ports after shutdown, at least in many situations.
Of course be careful messing around in the BIOS, you don't want to mess up something rather more critical.
I went through the same thing with a different USB powered DAC and did some reading and discovered something that I didn't previously know was even a thing, it might be useful to somebody here.
On many/most computers the USB ports will still be powered even when the computer is shut down. That probably isn't a big deal but of course the DAC will light up and the battery of a lap top will be draining if left like that for an extended period of time.
The option to have power at the USB ports can be controlled, at least in some circumstances and some ports.
My scenario is a HP Z Book but the same likely applies to many others with different ways of achieving it.
I did a Google search about turning off USB power at shut down and found a raft of information, most of which was not applicable to my lap top. All sorts of settings within the Device Manager - Universal Serial Bus Controllers and Control Panel - Power Options and so on which ended up in dead ends with comments about settings that were not even there or didn't do anything if they were there.
However, I ended up with success in the BIOS (Basic Input Output System) setting, at least for the "Legacy" USB-A ports but not the USB-C ports, I could work with that.
There was an option to turn off USB power from the two "Legacy" USB ports (the USB-A ports) in the BIOS, literally uncheck a box and reboot. I could not find options for the USB-C ports.
The management options within the BIOS seem to differ wildly between manufacturers so I can't offer specifics but if you are stuck with a device that is constantly powered from the USB there may be a way to manage the USB power available at the ports after shut down. It will probably take some research to get to the BIOS and then to the right settings in the BIOS but there may be a relatively straightforward way to achieve unpowered USB ports after shutdown, at least in many situations.
Of course be careful messing around in the BIOS, you don't want to mess up something rather more critical.
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