USB Hub Issue? Power Problem?

So I have a Startech 7-port powered USB hub that seems to only work when it's plugged in to the yellow "Always-On" USB port on the back of my Thinkpad W530.

If the hub is plugged into the USB 2.0 or 3.0 ports on the left side of the Thinkpad, the hub doesn't work.
If I plug the Startech into the hub integrated into my Dell monitor, which is in turn plugged into any port on my laptop, the Startech hub doesn't work.

Would this be due to some sort of power requirement? I'm testing these configurations using my iPhone plugged into the Startech hub in question, and a Dell keyboard in the same hub. The monitor hub was tested and is working properly.

Is this due to the Always-On port having a higher voltage or something? Or is my Startech hub just a crappy hub?

 

When you say powered hub, you mean that it has a power adapter that goes into a wall socket? If so, it shouldn't matter how much juice the USB port is providing since the hub has its own independent power source. If it has no external power source, then it could be that the port is not providing enough power. I've seen this happen on my Thinkpad Tablet 2 as well as on some devices connected on a pass through like your dell monitor (unable to start some external drives due to lower power).

The hub could just be a dud too, but better check everything else before.

Also, for the record, the voltage on USB is the same for any port (5 V), it's the amperage that the port can provide that is different, the pass through adds some resistance to the circuit which in turns means lower power provided to the device.

 

It has a power adapter, which is what confuses me.

 

Have you tried it with the the hub powered via adapter?

Usually powered hub is needed because a single USB port cannot provide enough current to the many devices connected via the hub.

That's where the AC adapter comes in, it provided supplementary power to the hub.

Let's say your PC usb port provide a maximum of 750mA and you have a hub that has 10 ports, and you have 10 usb drive that uses 75mA each, technically, the hub could power all 10 devices with out the assistance of and AC adapter.

But, let's say you have 2 external drive that uses 500mA each, the hub wont have enough current to power the drives at the same time, because it uses 1000mA, 250mA more that what your usb port could provide.

Also, power hub should just work with out external power also.

 

Have you taken a multimeter to the power supply?

 

I have the same question. As I know, the hubs with its power adapter generally has no power supply issues. So if I need, I always choose those with ports as many as 10 ports. Till now it works OK. Later , I can't promise.