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- USB port cant detect
September 2, 2008, 6:23 am
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i have acer veriton 7600g,, all of its usb port cant detect.. the
driver is already installed and device manager post it "device is
i also tried other usb disk , mouse keyboard but then still cant
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Thread archive: http://www.PCForumz.com/USB-port-detect-ftopict87550.html
Re: USB port cant detect
That is a known issue. There were a rash of failures of ICH5 Southbridges
in the last couple of years. Your computer uses ICH5 (as does the computer
I'm typing this on). The failure, at least to me, is indicative of
"latchup" failure. The second link gives an explanation (but a diagram
may have made the description easier to understand).
Failure can be at two levels of damage. In this picture, the
motherboard is basically ruined when the USB port fails. There
is a burn mark on the chip. If this happens, the computer will
no longer boot. It would need a new motherboard. There is no
way to predict how a given chip will fail - at least some
go in a spectacular fashion like this one did.
Many people suffer a less violent failure. What happens is,
the Device Manager continues to show the normal USB device
entries, and all are reported as functional. When the chip
burns inside (hidden from the user), power to the USB I/O
pads is lost, and then the USB port can no longer connect
to external devices.
A workaround, for desktop systems, is to install a PCI USB2
card, to provide some replacement USB ports. This will not
help you, if the computer uses a USB keyboard. At least
for the purposes of adjusting the BIOS values, a working
keyboard connected to the Southbridge would normally be
needed. If you currently have a USB keyboard, you can
always plug in a PS/2 keyboard, for those occasions
where the USB one is not working. I normally use a PS/2
keyboard, so this would not prevent me from having full
keyboard functionality in my BIOS screens.
Only one company (Gigabyte) has publicly acknowledged there
is a problem. I haven't seen anything on the Intel site. On at
least one Asus motherboard, they actually replaced the Southbridge
chip under warranty - that is not exactly an easy repair to do,
as there is a risk the motherboard will be damaged while
repairing it. There are a large number of contacts on the bottom
of the chip. The motherboards use a pretty poor quality of
printed circuit board, which makes the repair more dangerous
If the warranty is expired on the computer, it is hard to predict
whether there will be a "hidden warranty" coverage for the failure.
I expect the computer companies get some kind of compensation from
Intel, when servicing these failures - if they didn't, there would
have been more bad press about this problem.
Since you did not mention having a problem booting the computer,
then my suggestion would be to install a PCI USB2 card, to take
the place of the non-functional USB ports. As a rule, all the
USB ports on the Southbridge fail at the same time. I haven't heard
of any partial failures. They all seem to go at once.
A new PCI USB2 card will cost about $10. This will place four
connectors on the back of your computer. You need an empty PCI
slot, to be able to use this.
"SYBA PCI USB 2.0 4+1 port controller card Model SD-V2-5U
Based on NEC uPD720101"
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