USB ports unstable behavior

[dbal]

So, let me clarify on the "unstable behavior" thing. Some time ago, the usb 2.0 ports on my pc, started popping the well known "this device can perform faster" message, when connecting my nexusS smartphone. After playing around with different devices, ports and cables, the only consistent repetition of the problem is when connecting any 500mA device, like smartphones, my Xoom tablet, USB cam etc while my USB HDD, mouse, printer, flash work flawlessly even if I reconnect several times back to back.
Any idea for the underlying cause?? Thanx in advance!

 

[sm625]

Is it all ports? The ones on the back and the ones that are routed to the front?

 

[dbal]

Yep, problem comes up on all ports, even the side case ones, that are based on a seperate motherboard position. My guessing and googling so far has driven me in two paths - PSU and dying motherboard which both cause some kind of electrical instability...but cant say I am certain...

 

[bico]

that message means device connected to usb1 chip instead of the faster one so my guess is failing usb chip on the motherboard

 

[sm625]

One of your capacitors probably failed, leading to loss of regulation at higher load current. Its probably not even an electrolytic that failed, its probably a smaller tantalum or even a ceramic. Ceramic caps crack pretty easily, especially if the motherboard gets flexed. It is harder to spot defects in those compared to electrolytics, but it could be worth a look. They can break right off the board too. For example:

I think if one broke it is probably a bigger one than these.


You could also try a powered usb 2.0 hub. Maybe it will allow your devices to run at full speed if the power load is taken away from the motherboard.

 

[corkyg]

The easy fix is a powered hub connected to a good USB port.

 

[bico]

as long as the usb2 chip is still ok, otherwise it will fail/fallback to usb1

 

[dbal]

coming back to this thread after taking a cheap, fast measure. Unplugged everything from mobo usbs and plugged all devices on a PCI USB add on card. The "device can perform faster" message was gone, but problems came up again with absolutely RANDOM disconnections especially over my external usb HDD, which prevents me from getting my scheduled system image backups
Could this be a final diagnosis that rules out the motherboard and points us clearly to the PSU since all is connected over the PCI card? Before I bet my money on a new PSU...

 

[CliveE]

Had the same problem. In my case the first memory bank is necessary for stabile USB. Years ago I had a bad 512MB in it and then later i managed to put a bad 2GB memory in it. Now the 2GB is broken and I don't need the PCI USB card anymore. You have to fill all of the memory banks, and memory should be working or really working for the board. The bad memory just didn't run sometimes, but then was okay - and memtest was no problem. But it was bad enough, make the USB go on an off. The worst is, when bank 1 - closest to the CPU - is empty. This doesn't work at all - USB chip seemed damaged - but it isn't works fine now, surfing with it - no interruptions. After years of using a PCI USB, having all the time problems with SD cards. Should have knows this 5 years ago. I noticed back then, and had in mind, PC runs better with both memory banks full - but that was all. All the bluescreens I had because of USB conflicts. Wasted years, but now all seems fine.

 

[mikeymikec]

The Nexus 5 will report "this device can perform faster" because it's a USB 3.0 device but without a full USB 3.0 interface. If you read the whole message, it should say something like "if you connect it to a SuperSpeed port".