Any suggestions to fix this iPod/PC charging problem

Factual Questions
1

On my old PC I just connected the PC and laptop with a USB cable and it started charging.

I have a new PC and this doesn’t happen. The iPod icon doesn’t show a charging state at all unless iTunes is open on the PC, and even then it won’t charge except during and for few minutes after synching.

Other maybe relevant thing –

  1. I have an optical mouse that needs a constant electrical flow for the laser, and it works fine in both USB ports. So there is power getting out of the USB port.

  2. I use the same cord with an AC adapter, and the iPod charges normally, so the cable is good.

  3. Charging on old laptop still works as it did.

  4. From this I’m guessing there is some kind of software switch on the iPod or in iTunes that tells the iPod when to draw a charge, and maybe interacts with some Windows setting related to USB port operation. But I can’t find any such controls or the suggestion of them in either iTunes or Windows.

2

I’m not sure if your new PC is a laptop or not, if it is a laptop ignore everything I’m about to post.

Are you using the USB ports on the front or rear of your PC? Some motherboards limit the power that can be drawn through the front ports. This would mean enough juice for your optical mouse, but not enough to charge an ipod. Try plugging the cable into one of the rear ports and see what happens.

3

The iPod needs the data lines biased in a particular fashion in order to charge.

You can read more than you want to know about it here.

I’m not sure why a newer machine would have problems that an older one didn’t

4

It’s a laptop, there are only 2 USB ports, and neither will charge the iPod.

5

Sounds like you have low power USB ports on your new laptop.

6

Is there more than one kind? IOW, are you saying they are designed that way, or are putting out low power due to some kind of defect? I

7

The Universal Serial Bus is no longer entirely universal - there are a few kinds of USB ports now. Aside from the original spec, 2.0 and 3.0, there are high and low powered ports, as well as yellow “always on” ports for charging phones, etc.

8

Missed the edit…

If you’re lucky enough to have an orange USB port, that’s a high-current port that can deliver more than half an amp. Some of these can deliver as much as five amps as a charge port, or an amp and a half while acting as a data port. (For reference, a new iPad draws about 2.1 amps.)

Much more than you ever wanted to know about USB.

9

Ok, an odd update. I was looking through the Dell suppoort website to determine the specifics of my USB port, found a hardware diagnostic specifically for USB ports, and ran it. It did not find any faults, yet during the process I plugged in the iPod to a port (as instructed), and it detected it. Just detecting it means it passed the test (I think). But the good news is that my iPod now shows as charging, and continues to charge even though the diagnostic program is done and closed,

The other odd thing is that I know the PC detects the iPod under normal circumstances. I could look in Explorer after I plugged it in and it showed up as a new removable drive.

So after I run a charge for a while, I’ll shut down the computer, restart it and see if this changed behavior improves. I hope so, it seems kinda crazy to have to run a diagnostic that doesn’t detect any problems but still changes how the computer works, just to charge an iPod.

10

My USB ports are 3.0, BTW. Does this mean anything other than a presumably faster data transfer rate? Are they downward compatible with older hardware – I have a quite old 80 ghtz iPod Classic.