Something that has concerned me. I see these hubs with several USB ports. One use for them is larger USB memory devices. These get warm indication need for some amount of power. If a hub gets both its power and signal from the same connector(source) is the average PC able to sustain the current drain on a single USB port.
USB HUBS _ Powering?
- Thread starter boleyd
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johnwhelan
Well-known member
No, think about it the USB standard says you should be able to draw so many watts from a USB port, if you try to draw the maximum amount from each port you can't do it. If the USB devices are separately powered then they work or if the total draw is less than the standard you'll be OK. By the way not all USB ports on PCs meet the standard for power available.
I use a powered hub from Anker.
Cheerio John
I use a powered hub from Anker.
Cheerio John
capdiamont
Active member
If you are drawing a lot of power from a hub, the power from the computer will not be enough. Best to run powered USB hubs whenever you can.
You have to be careful with the off brands because some don't follow the specs and can fry components.
I have one that works great for about an hour....then it can do all sorts of weird stuff that you wouldn't think a hub could do. Like causing an internal HD used for storage to cease to exist! That was my best one: this machine has 2 HDs in it....but the hub can cause one of them to become invisible: you cannot see it on ANY software! Unplug the hub and the second HD suddenly exists again!
That's not good. I wonder if that's a power issue caused by a failing component. I had an external USB case short out internally and kill my motherboard one day after working perfectly fine for ages, so I would keep my distance if I were you with that one.
That one was permanently retired after figuring out that it was the problem. It was then placed into my "You Wouldn't Believe What This One Did" box. I have run into many strange hardware things like the HD that worked perfectly as long as it was the only drive. But as soon as another drive was added, one or the other would work, but not both of them. Finally, with an amp gauge, found that the bad drive which was only supposed to be pulling a little over an amp was actually pulling almost 5 amps thus overloading the power supply.
I would've done the same.
That makes sense why the disk was acting the way it was. Good troubleshooting! Most people wouldn't think of doing that unless they work in electronics such as you and me.
I've seen weird stuff like that too.
My sister's ex-husband plugged in a firewire camera into my computer and the camera died. It turned out there was a bad filter cap on the board right at the connection. We could actually see that it was puffed up. The system always acted a bit off but we could never find it until we found the bad electrolytic cap. Upon inspection, there were many more bad electrolytic caps and I ended up replacing the motherboard. That was back when the bad caps made their way into circulation and that ultimately ruined many good companies too.
KotangaGirl
Pre-Grouping Railways Nut
Something I discovered with a supposedly good quality powered USB hub recently was that the output from its power supply wasn't necessarily friendly to all computers. It was perfectly fine when plugged into my CoolerMaster computer, but blew out a USB connection when I tried it on one of my old HP Xeons. The hub and the power supply were the same make and had come to me packed in the same factory sealed box and it wasn't a cheap brand either.
That little episode has put me right off using USB hubs except for the most mundane and low powered applications.
That little episode has put me right off using USB hubs except for the most mundane and low powered applications.
That's really nasty, @KotangaGirl !
That sounds like something wasn't grounded properly somewhere to cause that by creating a circuit that's floating above the ground point. This could be a fault from USB, the cable from the USB hub, or the hub itself. Given how cheaply made these devices are these days, I'd suspect the USB hub for having that issue.
Yup I was right. I just found this!
electronics.stackexchange.com
That sounds like something wasn't grounded properly somewhere to cause that by creating a circuit that's floating above the ground point. This could be a fault from USB, the cable from the USB hub, or the hub itself. Given how cheaply made these devices are these days, I'd suspect the USB hub for having that issue.
Yup I was right. I just found this!
why did my powered usb hub kill my computer's usb port?
Curiosity kill the computer port. But why? I bought a 4 port USB 2.0 hub. I removed Vcc and Gnd from the Type A connector of the hub. Then I powered the hub and inserted a USB stick into one of th...
electronics.stackexchange.com
KotangaGirl
Pre-Grouping Railways Nut
Thanks for checking into that John. My daughter and I first had the thought that the earth connection in the wall plug was faulty, but when we tested it with an earth tester all was fine. This left me with an expensive USB hub that was more than likely now only good for being a paper weight since there was no way that I could trust it anywhere near one of my computers anymore.That's really nasty, @KotangaGirl !
That sounds like something wasn't grounded properly somewhere to cause that by creating a circuit that's floating above the ground point. This could be a fault from USB, the cable from the USB hub, or the hub itself. Given how cheaply made these devices are these days, I'd suspect the USB hub for having that issue.
Yup I was right. I just found this!
why did my powered usb hub kill my computer's usb port?
Curiosity kill the computer port. But why? I bought a 4 port USB 2.0 hub. I removed Vcc and Gnd from the Type A connector of the hub. Then I powered the hub and inserted a USB stick into one of th...
You're welcome, Annie. I can see you and your daughter were looking in the right place as well. Being cheap electronics, though the first thing I always suspect is the devices.
Ground faults on devices are very unsafe for humans and equipment alike. I got zapped when working on a video terminal that wasn't grounded. The unit was missing the chassis ground strap and the anode wasn't connected to the CRT properly. I got called from field service to take a look at the unit with a screen that was rolling as if the vertical hold was bad, except there was no adjustment on the units for that. When I touched the unit to turn it around so I could see inside the back, I got hit with a jolt that put me right on my backside. I was then rushed to the ER. I was out after a few hours and was fine with no issues, but that jolt of 19KV sent me flying! I was very nervous afterwards when I worked around opened-up terminals and got teased a lot by my coworkers.
I wouldn't have gotten zapped as bad IF I had followed the proper protocols. When working around equipment, especially CRTs and other high voltage devices, always use one hand and put the other in your pocket. The reason is this prevents a direct jolt across the chest and while the zap may hurt, it goes to ground down one side only. I was dumb and grabbed the unit with both hands and turned it around to look inside. I could have sent my heart into orbit and was very lucky with this ordeal.