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Sometimes when I power off my PC some lights on the keyboard stay on. It's pretty random which ones, though I suspect it has something to do with what lights were on just before the shutdown (if I vigorously follow that they are all off while the PC is shutting down then they stay off). Not that this would change anything, but it is annoying. Why does this happen and how can I avoid it?


Added: I know that I can turn off the power completely to my computer and it will go off. That's not the point. Actually, I even want my keyboard to have power, because I use it to turn on my computer (the power button on the case is difficult to reach). I just want the lights to go off. Or at least understand why this happens.

Oh, and it's a PS2 keyboard.

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Do you power off at the wall socket or just do a software shutdown? The former should remove all power from the machine (after a few seconds for capacitor discharge) unless you have a UPS. A software shutdown does not remove (all) power from the motherboard. –  mas Sep 3 '09 at 8:59
    
I know that. A keyboard light without a power source would require an exorcist, not a SU post. :D But I do not want to remove power from my PC fully. That would be several orders of magnitude more annoying than the silly little light. –  Vilx- Sep 3 '09 at 9:10
    
If it's running a Unix-based OS, you could try adding setleds -num -caps -scroll to the shutdown script (/etc/rc.local.shutdown on some distros) –  grawity Sep 3 '09 at 13:07
    
Are there other keyboards you can try on the computer? That would at last help to determine if it's a mobo issue or a keyboard issue. –  Sidnicious Sep 3 '09 at 13:08
    
I've known this to happen on different PCs with different keyboards. –  Vilx- Sep 3 '09 at 13:21

6 Answers 6

About the why, I would simply go with the fact that as your keyboard is still powered, it just kept its previous state. I don't think the OS has a routine on shutdown to deactivate the lights, simply.

About a solution, I think we have to search in programs able to switch the state of these "flags" on keyboard, and a possibility would be to make a script to turn off lights with such a software, in a script to turn the computer off. (I will try to find such program)

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It is as mas mentioned, when you shutdown your computer. Your motherboard still have power from your outlet. Some motherboard stop supplying power to any USB devices after it has been shutdown (boards with USB power management). However, most motherboard still power USB ports as long as the power supply has the power to power the board!!! (because the port are powered by power supply unit)

Solution: Unplug your power supply or if your power supply (located at the back of your case) has a switch then you can simply turn that off (almost all have)

Hope that answers your question.

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It's a PS2 keyboard. And I actually want it to supply power to the keyboard, because I use the keyboard to turn the computer on (the real power button is waaay down beneath the table). I just want the lights to go off when I turn off the PC (not sure which ACPI state that is). –  Vilx- Sep 3 '09 at 10:22
    
This sounds more like an issue with the Keyboard itself than the computer then. –  Will Eddins Oct 1 '09 at 14:45

I ran into this myself on my new computer that I just built.

I have a Das Keyboard which I have plugged into my computer's PS/2 port. When I would shut down, the keyboard lights would remain lit. I figured out what to do to fix it, though. My motherboard is an MSI 890FXA-GD65 AMD Socket AM3 and the CMOS setup utility was made by American Megatrends. If I launch it by hitting DEL when it's doing its POST, I found that what was set under Power Management was to have it listen for wakeup events from the PS/2 keyboard and have the BIOS trigger the state change. This apparently meant that it would be still feeding power to the keyboard for the purpose of being able to trigger on a key press, and hence the keyboard lights would remain lit, even when powered off.

What I changed to fix it was to simply set it to allow the OS to trigger the state change out of sleep mode. Now, when the computer powers off, the keyboard lights do turn off. When I set my computer to go to standby, the keyboard lights do remain lit, but that's the only situation where they do, now, which is how I prefer it.

Without knowledge of what you have available to you in your BIOS setup, I cannot say that you can do the same thing. However, if you are able to boot the computer using a keyboard key press, then you likely have that ability. However, since the BIOS already has to boot the computer from the off state, I think you likely will simply be stuck with a keyboard with lit lights. The best recourse in that situation, in my opinion, would just have the BIOS not start up with Num Lock on by default, and to make sure they all are off before you shut the computer down. For added measure, you could likely get a program that turns the lights off (or even write one yourself, as it probably is just a simple write out a few bits to memory).

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I believe it is actually a BIOS feature in some motherboards. In the BIOS, you can make settings that start the computer when a key is pressed on the keyboard... In order for that to work, you need power. (I understand that you already know this...)

I think the reason that the lights stay on is because this setting doesn't control the keyboard specifically, but rather controls the power to it. With the setting enabled, your keyboard never loses power from the time you are using it, to the time you are booting, so I can only assume that the BIOS manufacturers made it so that the keyboard settings don't reset on every software shutdown. I have a computer that does something similar, but my motherboard settings do reset the lights.

Perhaps if you wanted to know more, go to your mobo manufacturers website and ask about it.

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This is most likely just a quirk with this keyboard. My motherboard supplies power to the USB while off, but my keyboard properly keeps the lights off until an OS has booted up. Sounds like this keyboard is just made to always stay on and isn't meant to be always supplied power. –  Will Eddins Oct 1 '09 at 14:47

I had the same problems, but i fixed" go BIOS setup in power management you will see EuP Ready make sure you enable that and it will fix the problmes

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I think that it is waiting for some process to end completely. You should not worry about that. Just let it take its time to close.

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Sorry, I guess I wasn't clear enough. The computer is most certainly powered down - all fans are off, drives are stopped, power light is off, etc. –  Vilx- Jan 21 '12 at 22:26

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