When is a USB2 port not a USB2 port?

[yalamo]

I just purchased a 320 GB portable external hard drive with a USB2 connection. I connected it to a USB port on the front of my PC (I have a Pentium 4 with WinXP SP2, and all my USB ports are supposed to be USB2). It didn't work. Windows went wild, refusing to copy files, showing the external drive in Windows Explorer, then not showing it, then showing it again, etc. So I unplugged it (it also refused to safely remove the external disk). Then I tried plugging it into the second front panel USB port. Same thing.

Then I tried plugging it into the last available USB port on the back panel (there are a total of 4 there) and it worked! Now it works fine.

I use the front panel USB ports a lot for my SD card reader and Flash Memory stick, so I know they work. Can someone tell me why they wouldn't work with the external hard drive? I was told that that USB ports acquire and remember characteristics of the drives that are plugged into them, and that this was my problem. If so, what should I do when I take the drive to another computer? How do I know which USB port to plug it into?

Or is it possible that the front USB ports are USB2 and the back ones USB1, something which would not bother Flash Memory, but does bother hard drives?

 

[SjrH]

Is the external drive powered from the mains?
I have a similar problem if I try to use an external drive without mains power (using the USB to power it) on the front panel ports as they are connected with a fly lead to a connector on the motherboard which causes a power surge to the usb hub (which is essentially all it is).

Connecting to the rear ports is fine as they are indpendently powered from the mainboard.

Could also be the difference in USB port types as you say.

[small]have you turned it off and on again?[/small]

 

[yalamo]

Yes, it's powered from the line. I don't think a USB output would have enough current to drive a hard disk.

Still, I would like to know how I can tell which USB ports on another PC will function correctly with my external hard drive before I hook it up to the other PC.

 

[BadBigBen]

Some PC cases use cheap wiring, which causes some USB2.0 capable devices to go haywire... that is why there are also two different standards on USB extension (or connection) cables out in the wild...



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[yalamo]

BadBigBen, thanks. It very well could be something like that. My PC is a generic, and while it;s held up very well over the last 4 years, it could be a problem of shielding or something like that. It's one possibility.

 

[CCCarson]

Yalamo, what you discovered is actually the usual configuration on a computer case. USB 2 at the back; USB 1 at the front. BUT, when I say "is", I really mean "was". Zillions of computer cases of not too many years ago conform to that.

I carry an extension cable with my USB stick, which is handy for connecting to the back. USB stick-users have to conform to the way things are, rather than to what might be more ideal.

The USB 1 ports are good for a variety of things, including many printers.

So, not to worry about your system. There are quite a few million others just like it. If you decide to buy a hub or an extension cable, however, just be sure it is indeed USB 2; occasionally marketing or vendors are dishonest about this.

 

[yalamo]

CCCarson, thanks, you've cleared that up for me. I suspected something like that. As I said, I've been using the front USB ports for my USB stick, which is USB2, without any problems. It may be slower than using it with a USB2 port, but untill now I didn't notice it, since It worked OK and I had no basis for comparison with respect to speed. What I didn't know couldn't hurt me.