Curious which mobo brands leave USB power on after shutdown?

[bgc99]

I've seen posts that indicate Asus may have this problem, wondering which others may as well? My current board is an Asus A8N-SLI Premium and it doesn't leave the usb power on after shutdown but it does have settings for wake on keyboard and wake on mouse that are disabled in bios.

I've seen this attributed to the mobo and also to particular power supply/mobo combinations. This just seems strange, to me shutdown means shutdown.

My concern is on a new build I don't want to end up with a system that leaves the mouse and keyboard lights of after system shutdown.

Thanks,
BGC

 

[lopri]

Yes, shutdown should be shutdown. Wake-on USB keyboard/mouse is for "Sleep", or S3. Click on Start -> Mouse over to Shutdown and you may see "Switch users", "Restart", "Shutdown", "Sleep", etc. options depending on your OS' power plan. S3 should be available as an option on a modern motherboard, and it is desired by many as well, because it enables you to get back to work quickly without waiting for the OS' to complete its boot precedure.

S3, or Sleep, is also called "Suspend-to-RAM" because the OS saves wherever you left with to system memory. Since memory is volatile (i.e. you lose the data if you disconnect power), the PSU must be able to supply a tiny amount of power while the system is under S3. The PSU should also provide even tinier amount of power to the board's USB controller so you can wake the system up by clicking on a mouse or a keystroke. But it will not light up the mouse or keyboard.

 

[bgc99]

I was browsing some of the forums on the Asus site and saw more that one complaint about the keyboard lights and mouse sensors staying active after system shutdown.

It may have to do with the way the power options are set in the OS as you mentioned. I never use sleep, I always shutdown so I don't have the problem even with my Asus mobo.

I do recall when I first built it, when I was running memtest from a boot disk when I pushed the power off button the keyboard light did stay on but it hasn't happened since the OS was installed.

BGC

 

[Ross Ridge]

A modern PC never completely turns off all the power when you push the power button on the front or select shutdown in Windows. If you want to competely "shutdown" the system you have to use the switch on the power supply at the back. Otherwise the power supply will continue to supply a small amount of standby power so that devices like keyboards, mice, ethernet cards, modems and most importantly the button on the front of your case can turn on the computer.

Some motherboards have jumpers that can enable or disable sending standby power to the PS/2 connectos and/or certain USB ports.

 

[bgc99]

I know they're never completely shutdown. I've never had one that would leave keyboard lights on and mouse sensor active if you didn't want them to be but apparently others have run into this.

I just want to make sure when I build a new one that I don't end up with this situation.

BGC