Hi guys!
Something weird happened, I hope someone can explain me what has happened... and if there's some workaround...

I have a notebook with an USB 3.0 port. In this port, there has been attached for ages an usb 3.0 hub, with 4 ports. Each port has it's own one/off switch and each has a blue led to indicate if it's on or off...

So, I'm using it this way forever with 3 usb devices plugged in it working perfectly.

Is has a power connector, maybe to provide extra power in case of connecting some hard disk, dvd unit. I never needed to use this power port (on the hub)

So a few days ago I tried an USB 3.0 to HDMI converter, so I could attach one more display to my notebook. I already have one extra display connected to it, using it's available hdmi port. So I wanted one more display.

This adapter integrated perfectly to my Windows 7.0, software worked perfectly, but never an image was displayed on the extra monitor.

So I tried to power my USB 3.0 hub, to check if the monitor was not receiving the signal due to lack of energy.
As I didn't have it's official 5V, 1A power adapter, I used one I had laying around. I checked the polarities and plugged into the hub's DC port.

The blue lights on the hub (connected) to the notebook went off. I removed the power supply from the hub and it's light were stil off. They used to be on when connected to the USB 3.0 port, even with no extra power supply.

I changed the polarity on the dc supply and plugged back into the HUB. All lights were on and the hub was working normally.
Still no video from my hdmi adapter, so I guessed the video adapter had some other kind of problem, but not related to USB 3.0 power.

Now the weird thing. Since then, my HUB only works, and it works normally, when connected to the 5V power supply.
If I disconnect the power supply from the HUB, it's like the notebook's USB port is dead. If I connect an USB 3.0 HD directly to the notebook's USB 3.0 port, the HD doesn't even turn on, it's little led doesn't lit, and it doesn't get recognized by windows. If I plug the HD into the HUB, and supply the HUB with 5V from an external power supply, the HD get's recognized and works perfectly.

So my USB 3.0 port now works only through a powered USB hub...

Can this be fixed? it seems it lost the ability to provide power, bit still works if outside power is provided...

Thanks for reading it all... i hope there's some solution to get my USB 3 port back to it's normal state...

Thanks a lot, Rodrigo

 

Board level repairs to a modern laptop are extremely difficult, in large part because you can't find schematics but even if you know what needs fixing it's still a challenge. There may be people that have the chops but I wouldn't expect them to be cheap.

 

Your USB ports could be on a daughter card in your laptop The polarity reversal probably did something in. The USB 3.0 port can typically generate a lot more power than a USB 2 port.

 

Your USB ports could be on a daughter card in your laptop The polarity reversal probably did something in. The USB 3.0 port can typically generate a lot more power than a USB 2 port.

Hi! Unfortunately only the 2x usb 2 ports are o a daughter card... the only usb 3.0 port is soldered to the main board...

But how come this usb 3.0 works normally if connected to powered hub? Alone itself it doesn't work. Over an unpowered hub also doesnt even get recongnized...

Weird

 

The data path wasn't damaged, only the power supply. They're separate functions on different wires.

 

The data path wasn't damaged, only the power supply. They're separate functions on different wires.

I thought so.. didn´t know if it was possible!!

I think I´ll leave it this way then... To find and replace a motherboard for this sole reason would be difficult and expensive... (it´s an Acer V5-171).. And it seems to be working fine with the (now powered) HUB...

The other weird thing is that, when I plugged the power supply with the polarities reversed on the HUB, the HUB itself remained perfectly functional... but the USB 3 port on the notebook suffered... So the hub protected itself, but not the notebook...

Thanks for your support guys...

 

So the hub protected itself, but not the notebook...

That's not terribly surprising. A hub might be expected to suffer reverse polarity hookups, and be designed to survive that, while a notebook designer might not have chosen to protect against a reverse-polarity hub being hooked up.

 

That's not terribly surprising. A hub might be expected to suffer reverse polarity hookups, and be designed to survive that, while a notebook designer might not have chosen to protect against a reverse-polarity hub being hooked up.

Yes...sure, makes sense... but... the hub designer could have designed the hub to protect itself against the polarity reversal and not allow this unwanted energy to back-flow to the computer...

 

Yup, that would have been nice.

 

Yup, that would have been nice.

As said before, my usb 3.0 port is working only with an auxiliary dc suppy., through the powered HUB...
But I have just realized now that... both of my USB 2.0 ports, on the other side of my notebook, don´t work anymore..

So, when I plugged the DC backwards, it may have fried all usb power supply !

On my notebook, Aspire V5-171 (i3), the USB 3.0 is soldered to the main board. But the USB 2 ports are a separate board... Anyone knows if just by replacing the extra USB 2.0 board it would fix it? I mean, the USB 2.0 separate board would have it´s own power regulation, or, I would need to replace the mainboard anyway?

This is a link to this usb 2.0 board: Is there any power circuit to it?

http://www.ebay.com/itm/Acer-Aspire...350710?hash=item211e9a51b6:g:2fgAAOSwUKxYfHQq

Thanks a lot!