YTFC Forum

GlovedBildo · Joined: 08 Jan 2006 Posts: 84 Location: East Coker

Basically, any help i'd be extremely grateful of....

Whenever I plug i nany sort of storage devide into my USB ports (my Ipod or a pen drive or anything like that) it'll say that the hardware has malfunctioned and windows cannot recognise it. Even though it is perfectly good working order.

However,

If the piece of Hardware is plugged in when the PC is off and tehn I turn it on, it works normally.

not a total crisis, but a total pain in the *rse! I have no idea hat todo because i'm useless with PC's when they go wrong :wink:

Thanks in advance

bowerboy · Joined: 08 Jan 2006 Posts: 619

I am not a genius but I know a site that is full of them!

http://www.theeldergeek.com/forum/

They are very helpful and should be able to sort out your problem for you ;-)

darren · Joined: 28 Dec 2005 Posts: 334 Location: Yeovil, Somerset

The problem is because your USB ports can't handle the amount of power being drawn.

There is a limit on the amount of current being drawn per port. When you plug a device in, the USB controller will measure the amount of power being asked for, and if it exceeds a certain limit, it will disable the USB port and report the device as faulty. There is normally a small surge when the device is initially connected, this may have taken the current over the limit.

When the device is already plugged in before the PC is switched on, by the time the USB controller 'polls' the USB port, the current drawn has already stabilised, and it's likely to be under the limit.

You tend to get this problem if you use unpowered USB hubs, or high current devices such as USB lights or if you charge your phone from the USB port.

The best way around this is to get a powered USB hub. USB devices will then take their power requirements from this, rather than drawing it from the PC. Don't get the cheapest you can find, as you'll end up with the same problem.

GlovedBildo · Joined: 08 Jan 2006 Posts: 84 Location: East Coker

Thanks fellas

GlovedBildo · Joined: 08 Jan 2006 Posts: 84 Location: East Coker

darren wrote (View Post): › docWrite("quote")The problem is because your USB ports can't handle the amount of power being drawn.

There is a limit on the amount of current being drawn per port. When you plug a device in, the USB controller will measure the amount of power being asked for, and if it exceeds a certain limit, it will disable the USB port and report the device as faulty. There is normally a small surge when the device is initially connected, this may have taken the current over the limit.

When the device is already plugged in before the PC is switched on, by the time the USB controller 'polls' the USB port, the current drawn has already stabilised, and it's likely to be under the limit.

You tend to get this problem if you use unpowered USB hubs, or high current devices such as USB lights or if you charge your phone from the USB port.

The best way around this is to get a powered USB hub. USB devices will then take their power requirements from this, rather than drawing it from the PC. Don't get the cheapest you can find, as you'll end up with the same problem.

So does this mean that if I unplug other pieces of Hardwre it should be ok??

Or is this an accumulated thing?

It has now stopped recognising the ipod at all when plugged in before I switch the PC on :(

darren · Joined: 28 Dec 2005 Posts: 334 Location: Yeovil, Somerset

The power limit is per USB port, so it's unlikely that removing devices is going to help, unless you're using an unpowered hub on that USB port.

Over time, you can do damage to the motherboard if you draw too much power too often, this may be why your ipod is not being recognised.

It may also be that the ipod device driver may be corrupt. In device manager, remove the entry for the ipod, then plug it in. It should then recognise it again and reload the driver.