Now....you know how when something starts acting a little "weird", that you try and think when the last time was you made a change to your system? Recently I got a new printer, a Canon, model # MX870, USB connection.
The thing that has started acting "weird" is my keyboard: It will suddenly stop functioning, meaning, no response when keys are pressed. The keyboard is a Steelseries Merc Stealth USB connection, and it happens to be a keyboard in which the keys are illuminated, so, when it stops functioning, I actually notice its lights go out before I even need to press any of its keys to see that it's stopped functioning.
When this happens, the printer will also be turned on.
And besides the keyboard's lights going out (and of course there's no response when I press any of its keys), I hear that audible default sound that Windows makes when a peripheral device is turned on or off that's connected to the computer.
I've got lots of devices connected to my USB ports on my computer besides the keyboard & printer (mouse, illuminated mouse pad, web cam....and even an external HDD that I connect on occasion), but I believe ever since getting this new printer was the time that I noticed the keyboard acting up.
Can USB devices sometimes conflict with each other? Is it something that can be adjusted in the BIOS?
And BTW......this is just a stab in the dark, this theory that it might be the printer interfering with the keyboard; I'm just guessing.
USB devices don't normally interact with one another.
I wonder if it's due to power? USB devices draw power from the USB socket (to recharge phones, or spin a hard disk, or light up a keyboard, or provide light for an optical mouse), and there's a limit to how much power can be drawn. In theory there's supposed to be 500mA available per device, but some devices draw more than their far share, and it's not uncommon for the USB ports to have a limit on total current draw. It's possible the printer is tipping your machine over its limit.
You could try attaching a powered USB hub to the PC - one with a transformer that plugs into the wall - and attaching one or more of your devices to that hub. If all works again, maybe power was the answer.
Possible power problem? Well, my PSU itself is a good quality one. I learned years ago that it's not just what raw watts a PSU is rated at, but also the 12V rail that's important. I have a Corsair 750W.
But, I didn't know there's a limited number of amps per device. Perhaps you're right and this particular printer is "tipping" the limit.
On the back of my pc (motherboard), there's eight (8) USB ports; I'm using 5 of them.
On the front of my case (a CoolerMaster 932 HAF), there's an additional four (4) USB ports, but they plug into a different place on the motherboard than those eight in the rear.
You mentioned an optical mouse: I have a Razer Death Adder, and besides being optical, this mouse also illuminates a "pulsing" blue color.
You ask about the illuminated mouse pad? Why? I got hooked on the color blue
My Razer mouse lights up blue, my mouse pad lights up blue, my keyboard is blue....and I even have blue lights inside of my case; I'm a blue kind of guy.
Anyway, before I invest in a powered USB hub, I will be hooking up a wireless router to my PC. This Canon printer, besides having a USB connection, can also be connected wirelessly. I'll give that a shot and see if the keyboard losing connection goes away.