USB Controller problem

My 5 yr/old laptop (hp zv6130us) has 4 total usb ports. One of them, I believed, had died. No device plugged into it seems to work, however, I discovered that that usb port powers the device.

This malfunctioning usb port corresponds to the "unknown device" which upon inspection is one of the usb controllers. All of the other usb ports work, and the other usb controllers are recognised in device manager.

Also, this problem has remained throughout a reformat/clean install and before that, a bios reset (unplugging power/laptop battery) which each was done for other reasons. I will try the latter again later.

Is this hardware (bad controller), bios (doubt it) or what? One bad port isn't critical since the others work.

A USB port has four connections in it. Power, ground, data+ and data-. Without getting technical, it sounds like power and ground are okay, but one or both of the data connections might be bad on that port. If that's the case, the port can't recognize any USB device that might be plugged in to it. Basically, it can't negotiate with the device to set it up, so it reads as unknown.

That's the hardware explanation. It might be a weird driver thing instead, I can't be sure. If it's a hardware problem, there isn't much you can do about it, other than to double check the connectors at the motherboard and the port. If Wallon7's fix doesn't work, you may have to live with the port being shot. Sorry.

Mellon Head said:

A USB port has four connections in it. Power, ground, data+ and data-. Without getting technical, it sounds like power and ground are okay, but one or both of the data connections might be bad on that port. If that's the case, the port can't recognize any USB device that might be plugged in to it. Basically, it can't negotiate with the device to set it up, so it reads as unknown.

That's the hardware explanation. It might be a weird driver thing instead, I can't be sure. If it's a hardware problem, there isn't much you can do about it, other than to double check the connectors at the motherboard and the port. If Wallon7's fix doesn't work, you may have to live with the port being shot. Sorry.

I think you are right. Its hardware...this laptop's 5 years old and has been really used and subjected to many stresses (ie static electricity and being taken to school etc), so I'm not surprised that somehing has failed. Actually, it's the first hardware problem this laptop has had in the 5 years.

By the looks of it in device manager, 7 knows that the unknown device is a usb controller, it just can't make it work. "device cannot start," so it's not driver related.

I'll try to visually inspect the pins, but, I believe its a lost cause.

Yeah. The pins might be fine, but the electronics behind them might have failed for that port. There's no way to really know for sure, unless you've got a bent pin that you can straighten out.