How To Troubleshoot USB Power Issues
This is a brief video designed to show computer students how to troubleshoot power problem that they might encounter when there are too many devices plugged into one USB Hub.
Step 1: Introduction
Hi, this is Mr. Ford from mrfordsclass.com and in this presentation we're going to talk very briefly how to check the amount of power that your USB is using. You might have learned somewhere that your USB can attach 127 devices theoretically into one root hub. A root hub of course is the beginning of the entire chain of one USB port. You can have 127 devices plugged into that one specific chain. You might have four or three or more ports on your computer and each of these typically go back to one hub, so each hub has 127 devices that can get plugged into it. If you start to notice a problem with that one chain of USB devices you might need to look at the amount of electricity that's being provided. You might be aware that USB devices can get some electricity from your computer, so your webcam doesn't need to be plugged into the wall, it can get powered by your USB device. I think the best example currently of how USB device provides electricity would probably be the iPod. You can plug your iPod into your computer and it charges in that manner, it's getting electricity from your computer. So let's see how we can check to see if we have too many things plugged into our USB.
Step 2: Getting Started
You're going to want to go to your Control Panel. You do Start, Control Panel, and we're going to want to look at System, Hardware, Device Manager, depending on your computer this might take a couple of seconds, it's pulling up all the things you have plugged into your computer.
Step 3: Checking Power Output 1
Scroll down to the world of USB, Universal Serial Bus controllers, double click, and you're going to get a whole bunch of stuff. You want to look at the Root Hub. I'm going to click on it once, then I'm going to right click on it. I want to pull up properties. There's a little button that says Power. For example, I'm not using anything on that port. This hub is fine, there is no power being used on this port.
Step 4: Checking Power Output 2
Let's look at a different port. Click on it, then right click, Properties, Power, in this case you can see I have a mouse on there, I have a wireless mouse, it's using power. If I add this up, look at this, 500 is available, I'm using 50, I have alot more power I can use. But let's say I plug a mouse into this one, I plug in a webcam, I have to use hubs outside of the computer. Webcam, mouse, keyboard, fishtank, if you go to thinkgeek.com you can buy a fishtank that's powered by USB, a powered LED christmas tree, a cupwarmer, I'm not making this stuff up, I swear to you there are cupwarmers you can get for the computer that use USB. Let's say I have all these things plugged into the one USB Root Hub the power available is going to go down, go down, go down and go down until I'm out of juice here. So even though you can plug in 127 devices, you need to keep an eye on how much electricity is being used. You can get around this by using hubs that come with a power supply of their own. If you have to plug in a hub to an outlet you're also kind of recharging the whole thing so you can actually plug more and more in without having to deal with a power issue.
Step 5: Checking Power Output 3
Let's take a look at some other hubs here, Properties, Power, that one's empty. Properties, Power, that one's clear. I've got something plugged in here, USB Mass Storage Device, that's my external hard drive, so you can see that I'm using power in this case, and in this case. That's very briefly, how you check to see if a USB Hub is using too much power, not alot of techies know about this stuff, this is good stuff to know. The chances of it happening I would say, are rare, but it's one of those situations I would say if it is happening and you happen to know how to fix it you feel really really good about yourself and you get to charge the client alot of money. I'm only kidding, sort of.
Step 6: End
Anyways, hope you enjoyed it, we look forward to seeing you next presentation.
