USB hub fails with some devices
Posted on 2009-07-02
I am an independent tech. This is for my customer. I need an answer BEFORE I go onsite so there is no more info to provide you other than what is below.
USB devices work when connected to the 5 usb slots on the 64 bit OS and 64 bit HW Vista PC (a Sony VGC-JS100) that looks essentially like the flat panel iMacs that have been sold for the last few years). However, my customer has more than 5 usb devices so she bought a GE brand usb hub. When she connects more usb devices to the USB hub some problems occur; my customer was not specific. BUT IT IS NOT THAT THE USB HUB DOES NOT WORK AT ALL.
If devices are NOT connected to the USB hub, there are NO problems.
USB devices attached are keyboard, mouse, iPod, Printer, USB stick (also called flash drive I believe). Additonal USB devices are an external HD and more USB sticks. The brand for some or all of the usb sticks is ScanDisk. I do not know which are attached to the USB Hub and which to the PC and this may vary from time to time.
Also note that with the USB hub attached there are only 4 available USB interfaces on the PC so all USB sticks and the external HD go into the HUB (as the keyboard, mouse, iPod cable, and printer are probably permanenty attacvhed to the PC and then also the USB hub.
PLEASE CHOOSE ONE OF THE SOLUTIONS BELOW.
(1) MY OWN VERY LIKELY SOLUTION: Replace the GE Usb Hub with a SELF POWERED USB HUB because the PC does not supply enough power for all these usb devices (especially the external HD). A Self Powered USB hub is one with an attached AC adapter.
(2) MAIN REASON I AM POSTING HERE: Another solution has occured to me: The PC (either the Vista OS or the PC HW itself) does NOT support an unlimited number of USB devices and when the maximum allowed is reached, no additional USB devices will work OR one of the currently attached USB devices will fail REGARDLESS of whether they are attached to a USB hub or not.
(3) Some other solution you will provide me with.
PLEASE TELL ME HOW TO SOLVE THIS PROBLEM.