Dumb question that may belong in another forum..... Numlock light when PC is off ?

[enoy21]

I noticed on my daughters PC a month or so ago that her Numlock light started staying on when the PC was off.   I thought this was just an old keyboard issue or that the motherboards age was causing it, but since getting my WASD and using the PS2 feature I noticed that it's doing the same thing on my main rig. ( 2 years old and upper end )

The LED on the WASD is super bright when looking directly over it.  Literally like one of the LED flashlights causing a large halo on my ceiling. The brightness hasn't bothered me in usual function , but at night it's pretty bright.  

I noticed last night that by turning off the power supplies main switch ( not through motherboard power ) that It turned the light off after a few seconds.... Does this mean my MB has capacitors holding power where they shouldn't ?  I've never had this issue in the past and it just cropped up over the past few months on both PC's.

I've already verified that all of the " Power on when...." options are disabled in Bios so it's not waiting for a key press.

Just curious.

[BookOfGreg]

The PSU keeps parts of the computer powered such as USB hubs and PS2 ports and the LAN port because its possible to turn the computer on via keyboard or the internet.
The Razer Abyssus and Filco Keyboards also stay lit when the computer is off. Also my hacked xbox 360 controller won't stop vibrating on the desk if its still plugged in even when the computer is off which is.... entertaining.
Not sure if you can get your bios to power down peripherals when off or not. I just turn it off at the wall every night.

[enoy21]

Yeah I'm aware of the reasons when the Bios is set to " turn on by key press" , but that's been turned off since day one on both machines.  The thing that concerns me is that it's a new change.  It's not something that has been happening all along.   I noticed last night that even the USB port is doing it.  but again , once I turned off the PSU at it's own switch and let the capacitors drain,  the  Keyboard lights did not come back on, although I didn't turn the PC on and then off again for a full test.

[enoy21]

Well I don't really Faceroll when typing so the poll rate would be all that matters to me.  I don't know that I would ever notice much difference either way as I've been running USB for 4 years now.

[iindigo]

For some odd reason at this point somebody at OCN usually says that it raises the CPU utilization.  Lol.

That might actually be true. By architecture, USB makes use of your CPU - the more data it has to deal with, the higher the CPU utilization. External HDs and other high-data devices are naturally the worst offenders.

This is part of why I've always preferred Firewire for anything more demanding than a keyboard or mouse. It's independent of your CPU entirely.

Anyway, at even 1000hz, the extra CPU use is likely pretty negligible.

[Findecanor]

The soft power off - thing has been going on since the ATX power supply standard. AT had a real power switch in the front panel.
I got all my hardware plugged in a power strip with a large foot switch, just so that I can make the computer power off for real.

[dorkvader]

Most laptops don't power the USB bus when "off" for obvious reasons.

I always make sure to flip the switch on my tower when I turn if off, even though it wastes little power, I like to make sure it's completely off.

I have, however, used it to charge USB devices when I'm away. The capacitors (and, to a negligible extent, the capacitance in other devices such as MOSFETs) will hold charge. Most properly designed devices have LED's and bleeder resistors to discharge them, but oftentimes, they can remain powered for a surprising amount of time when unplugged.

The best solution is, of course, to short all the power rails to earth, just in case. Make sure your fingers are in the way.

[hemflit]

Ok, OP, you don't seem to be perfectly clear on this, so: As it's been said, modern PSUs and motherboards keep some parts of the machine powered. When you physically cut the power, of course they won't be able to keep anything powered anymore, but there's a bit of charge left in a bunch of filtering capacitors. LEDs are very low-current stuff, so it's normal it takes a couple of seconds for them to drain the capacitors; if you had a little bulb there instead of a LED, of the same light intensity, it would burn through that charge so fast you wouldn't even notice it wasn't simultaneous with cutting the power.

Practical: if it's just light bothering you, well, press Num Lock to turn it off.
If it's bothering you to know that your computer is not completely off, do that footswitch thing with an extension cable.

I have no idea why this would suddenly start happening at some point, if you've been using the same computers the same way for 4 years. Mysteries!

[enoy21]

I just told my Fiance' that THE RIPSTER insists that I get a TKL Filco in brown switches with Ninja Keys......... She just doesn't understand....


Thanks for the replies everyone. I still don't understand why my other board wasn't doing this ... or why my Daughters Keyboard does on occasion. It's a Cheap Dell board and only does it on occasion.

[enoy21]

(((Nvm)))

[Clickey]

Some keyboards have a power button next to the Lock lights, it may be that yours shares power with numlock if it has always done it. The power light on the keyboard I am currently using is always on, as long as it is connected and the PSU is on.