Roy wrote:
> On Jun 22, 6:50 pm, Paul <nos...@needed.com> wrote:
>> Roy wrote:
>>> On Jun 22, 4:04 pm, Paul <nos...@needed.com> wrote:
>>>> Roy wrote:
>>>>> Hello group
>>>>> Recently I was dismayed why my USB drive was not recognized anymore
>>>>> by window explorer. Therefore if I plug it on the USB slot it does
>>>>> nothing. I searched the web for some ideas and came from this fellow
>>>>> which states:\
>>>>> 'A user of a company I know recently told me the following experience
>>>>> he had with a USB flash drive. The user traveled a lot and had a
>>>>> laptop that he used to connect to the company's network when he was in
>>>>> the office. And he was used to plugging his flash drive into the USB
>>>>> slot on his laptop so he could transfer files to another machine he
>>>>> used at home. But one day he came into the office, connected his
>>>>> laptop to the network, plugged in the flash drive and nothing happened
>>>>> -- normally an Explorer window would open displaying the contents of
>>>>> the drive. This was disconcerting, so he opened My Computer and
>>>>> discovered that the USB drive wasn't there. Puzzled by this, he took
>>>>> out another flash drive from his pocket and tried it, and this time it
>>>>> worked fine so he knew at least the problem wasn't with his computer.
>>>>> He was just about resigned to throwing out his first drive when he
>>>>> decided to send me a quick email detailing the problem. My immediate
>>>>> reaction too was that it was that the drive had failed, but then I
>>>>> thought about it some more. One of the key steps in troubleshooting
>>>>> problems is to ask what just happened. The drive failure had occurred
>>>>> after he connected his machine to the network, so could it be an issue
>>>>> with the network? I emailed back and suggested he disconnect his
>>>>> laptop from the network and try the flash drive again, and a short
>>>>> time later I received an email saying the drive now worked!
>>>>> Then it dawned on me. I told him to remove the drive, connect to the
>>>>> network and open My Computer again and look for something different.
>>>>> He did this and told me there was a new mapped network drive that he
>>>>> hadn't seen before. Aha! The network administrator must have modified
>>>>> their logon script to map a new drive on users' computers, and this
>>>>> new mapped drive probably assigned the very same drive letter that
>>>>> this particular user's laptop had previously assigned to his first USB
>>>>> drive. I told him to plug the USB drive in again, open Computer
>>>>> Management, and change the drive letter of the USB drive. He did this,
>>>>> and right away an Explorer window opened displaying the contents of
>>>>> his USB drive. Problem solved'
>>>>> Since I have never done such things these ideas sound strange to me.
>>>>> Meaning if the drive is malfunctioning it might have something to do
>>>>> with such and not a hardware fault.
>>>>> Although I was not using a laptop but just a desktop PC.
>>>>> I did found the computer management ( local) and had viewed the disk
>>>>> management on the right pane.
>>>>> Indeed there are letters that indicates one drive say for example
>>>>> Drive D and drive C which is easier tounderstand as well asthe Drive E
>>>>> and F and so forth. Previously the Flash drive was recognized as
>>>>> Drive G and J as well as drive H for another External hard drive.
>>>>> But now it does not recognized my flash drive.
>>>>> What I don't understand is why window explorer does not recognize my
>>>>> USB flash drive but still do with the other drives.
>>>>> Early this morning I was plugging these drives to the networked
>>>>> computer in the internet cafe and immediately it was not recognized
>>>>> and this kept me worried so when I arrived home I immediately plugged
>>>>> it and there the flash drive is not functioning or being recognized
>>>>> anymore.
>>>>> Could somebody offer me their advice how to sort this out
>>>>> What is going on?
>>>>> TIA
>>>>> Roy
>>>> Uwe Sieber has a web site, with that kind of information on it.
>>>> http://www.uwe-sieber.de/usbtrouble_e.html
>>>> From a hardware perspective, you can verify that the plugged in
>>>> device is being detected (communicated with), via UVCView program
>>>> from Microsoft. (Use the upper right hand link, to download an
>>>> executable for Windows 32 bit OS.) This is an archived web page,
>>>> as Microsoft has taken down the download page. There have been
>>>> several versions of programs that look like this one, and so far,
>>>> this one is the most capable. (Some of the originals, had limits
>>>> on the number of ports they could handle.)
>>>> http://web.archive.org/web/200705160...crosoft.com/wh...
>>>> If the physical layer is working, and the USB device can be
>>>> enumerated, and fill the window with data, then the problem
>>>> must be at a higher level in software. (In the picture here,
>>>> you can see VID/PID 0x0ECD 0xA100 device has been detected, and
>>>> the presence of the Endpoint Descriptor presumably means a
>>>> communications path is set up.)
>>>> http://www.die.de/blog/content/binary/usbview.png
>>>> For resetting the USB stack, usbman.com has a page describing a
>>>> procedure to do in safe mode. But this doesn't necessarily fix
>>>> everything. There are also instances where a driver cache is
>>>> corrupted, or the registry is locked to updates, that might
>>>> cause a procedure like this to not fix anything. But in those
>>>> cases, searching on the exact error text, will likely lead you
>>>> in the right direction.
>>>> http://www.usbman.com/Guides/Cleanup...%20Safe%20Mode...
>>>> HTH,
>>>> Paul- Hide quoted text -
>>>> - Show quoted text -
>>> Thanks !. sounds complicated and Microsoft is cautious about
>>> installing hotfixes which may not be the solution to the problem
>>> I did try to follow a certain procedure
>>> http://www.port-huron.k12.mi.us/tech...bflashdrivetro...
>>> But it when I right my computer- choose manage- Storage- disk
>>> management
>>> Then I right clicked the listed removable disk then change drive
>>> letter and paths
>>> And want to assign a new drive letter.
>>> I was given a warning that changing the drive letter might cause
>>> problem that the hardware connected might no longer run so stopped
>>> there.
>>> I also tried to create another drive letter but it says the letter was
>>> not recognized.
>>> Creating a new folder needs that you need another path, but when I
>>> browsed I only find that there are two path- the C and D drive.
>>> So I got lost here and would need some suggestion from people that are
>>> familiar with this methods.
>>> Thank You!
>> Have a look at this page. The Drive Letter Manager
>> might be able to change a USB drive letter for you.
>> I haven't used it, because I don't have any USB flash
>> devices here.
>>
>> http://www.uwe-sieber.de/usbdlm_e.html
>>
>> Paul- Hide quoted text -
>>
>> - Show quoted text -
>
> Thanks, I will have to read first the literature about its use.
> BTW, is there anybody here have experience about USB drive
> overvoltage? What I mean I am not discounting the fact that the
> desktopPc might have fried circuitry and this is an additional worry
> for me. I was thinking that some computers might have higher USB
> voltage rating for USBs than laptops?
> Is there a likelihood for such to happen?
> I just hope that this hardware is still intact...

The USB connector consists of +5V, GND, D+, and D-. Two power
signals and two data signals. The power level is a standard, whether
desktop or laptop. A high power device may draw up to 500mA of
current, and the total maximum power of 2.5 watts is just enough
to operate a modern 2.5" hard drive.

A USB device can be damaged by handling, such as dropped and broken.
Or static discharge could damage a device. But the
operating voltage should be the same on each computer. And
the connectors seem to be well designed, at least compared to
some more problematic connectors (Firewire).

The reason I wanted you to use UVCView, is to see if any low
level communication was happening or not. If there are no
endpoints and no enumeration data being shown, for a plugged
in USB device, it could be a hardware issue. If the right hand
window in UVCView has data in it, then there is hope that the
USB device is not completely dead.

The foreign computer could also have malware or a virus on it,
and a software like that might erase the flash device. I suppose
a device could be "killed" by being reconfigured, but I don't understand
how those tools work. It is possible to change the declared size
of a USB flash device (fraudsters on Ebay do that), so there is
some kind of interface to USB flash sticks, that hackers understand.

The only "frying" I've heard of, is Intel ICH5/ICH5R Southbridge
chips, can have their USB ports fail. When that happens, all the
USB ports on the computer, fail to operate. No plugged in device
will be recognized at all. You would not see any activity in UVCView.
In extreme cases, there will be a burn mark on the Southbridge chip on the
motherboard. But many of the ones reported to have
failed, don't have the burn mark - and that is good, because
if the chip is not burned by the failure, the computer
continues to be bootable. When it burns, it is finished, and
won't boot again. (I get to worry about this, because I have
that chip on my motherboard :-) )

Paul