I have a usb extension, it's 1 to 4 ports, the wire that came with it is one end with standard usb plug, the other end with a smaller one, i plug my keyborad, mouse, calibrator, and a card reader to it. it works fine, but, when i remove one of the devices, and plug my iphone to it, it cancel the sync process every time.
is it the cable with the smaller plug cause the problem, or all the usb extension is like that?
lack of power.
A better practice would be to use the usb plugs in your machine for key items like the Keyboard and mouse. Then use a separate hub for things you plug and unplug. Or if you have to use 2 hubs to separate "key devices" from removable devices.
Most likely the problem is a "cheaply made usb hub and connectors. So separate what you need to work from any "wiggling" cause by attaching and removing.
many cheaper usb hubs don't carry the power that is available on the ports built into a computer. and if they do, the already low power output is further reduced by the extra cables, connection points and the fact that it's now shared between 4 ports.
I had the same problem with my dell Axim X50V (Pocket PC) in that it would sync most of the time through a hub, but would not also charge or do anything else.
When connected directly to a computer, it was all good. And I also found that some usb hubs that come with power adapters are a better choice if you need to run that many devices, as they supply power separately and can therefore provide more power to the devices that need it.
dont forget your dividing the available power supplied from 1 port on the pc into 4 ports on the hub. The Iphone is likely going to want alot of that available power to charge itself, the calibrator may be using quite a bit of it as well.
You can get hubs with there own seperate power supply so you can use more power hungry devices.
If you just need the USB for recharging..... Check out something like this as it adds a USB plug to a power extension - Obviously not going to work if it needs to talk to the computer but good for power hungry recharge things.
