Urgent help needed: can't power off PC

Posted: 01-23-2004, 02:30 PM

Terry Pinnell

Guest
Posts: n/a

I installed a 4-socket self-powered USB hub today on my XP Home PC. My
various USB devices seemed to work OK (with exception of the new one,
a QX3 microscope, that had prompted the purchase, but that's a
separate issue). Here's a picture of it:
http://www.terrypin.dial.pipex.com/Images/USBHub.jpg

But, on switching off my PC, which seemed to power down as usual, the
amber and green power lights on the Mesh Athlon 1800 didn't go out.
And the PC wouldn't then respond to being switched on again. Nor did
Reset have any effect. Nor holding the power button depressed. Serious
worry and seems to defy logic.

The power lights would go out if I removed either the DC power to the
hub, or the USB lead connecting it to the PC. But even then the PC
wouldn't start up again. Removing and replacing mains plug, or on/off
button at rear of PC had no effect either

Somehow, after fiddling around, cursing a bit, it DID then respond.
But naturally I am now very nervous about switching it off. Using
Start>Turn Off Computer>Restart works OK - it's just the full Turn Off
that doesn't.

There's nothing to help in the single page 'User Manual' (headed USB
1.1 Hub GUH-01 GUH-02, with no contact or web info.

Can anyone offer any help please?

--
Terry, West Sussex, UK

Urgent help needed: can't power off PC

Responses to "Urgent help needed: can't power off PC"

Guest
Posts: n/a

Urgent help needed: can't power off PC

Posted: 01-23-2004, 08:40 PM

Have you checked/changed the power options in your system
Bios? Worth a look.

>-----Original Message-----
>I installed a 4-socket self-powered USB hub today on my

XP Home PC. My

>various USB devices seemed to work OK (with exception of

the new one,

>a QX3 microscope, that had prompted the purchase, but

that's a

>separate issue). Here's a picture of it:
>http://www.terrypin.dial.pipex.com/Images/USBHub.jpg
>
>But, on switching off my PC, which seemed to power down

as usual, the

>amber and green power lights on the Mesh Athlon 1800

didn't go out.

>And the PC wouldn't then respond to being switched on

again. Nor did

>Reset have any effect. Nor holding the power button

depressed. Serious

>worry and seems to defy logic.
>
>The power lights would go out if I removed either the DC

power to the

>hub, or the USB lead connecting it to the PC. But even

then the PC

>wouldn't start up again. Removing and replacing mains

plug, or on/off

>button at rear of PC had no effect either
>
>Somehow, after fiddling around, cursing a bit, it DID

then respond.

>But naturally I am now very nervous about switching it

off. Using

>Start>Turn Off Computer>Restart works OK - it's just the

full Turn Off

>that doesn't.
>
>There's nothing to help in the single page 'User Manual'

(headed USB

>1.1 Hub GUH-01 GUH-02, with no contact or web info.
>
>Can anyone offer any help please?
>
>--
>Terry, West Sussex, UK
>
>.
>

Terry Pinnell

Guest
Posts: n/a

Re: Urgent help needed: can't power off PC

Posted: 01-26-2004, 07:08 AM

<anonymous@discussions.microsoft.com> wrote:

>Have you checked/changed the power options in your system
>Bios? Worth a look.

Thanks, no I haven't. One more thing to try. Meanwhile, I now reckon
the power problem (as opposed to the microscope problem) is a
fundamental design issue, caused because the arrangement must look
like this:

External
5V supply
|
|
diode \/
--
| USB DC supply bus
|_____________________________
|
|
|
/\ diode
--
|
|
Internal
5V supply

The same behaviour occurred when I connected the powered USB hub to my
alternative W98 PC in my shed/workshop. It's incredible that the
manufacturer makes no mention of this fundamental flaw in the
accompanying sheet ('User manual'!)

I side-stepped the problem by removing the USB DC supply before using
Turn Off. In fact, I've now removed the powered hub altogether, as I
can't get the device (Digital Blue QX3 microscope) working on my XP PC
anyway, with or without it. And, after much effort and totally
inconsistent behaviour, I have got it working on my W98 PC, without
the hub.

=========================

On the microscope issue, elsewhere (the asus mobo newsgroup) I had a
post advising that sw doesn't work on XP. Which if so is a revelation!
I had given suppliers, Digital Blue, a detailed description of what
was happening on my XP PC, and they didn't so much as mention any of
those key points. In particular, no suggestion that sw doesn't RUN on
XP...

I had mixed success on my alternative W98 PC. I did get it running on
Saturday, after several hours involving half a dozen installation
attempts. But then when I tried Sunday it failed. Again it was that
'Having trouble communicating' message, as on XP, interspersed with
messages telling me microscope wasn't connected, when it plainly was.
I then tried with a self-powered USB hub I'd ordered specially, but
that gave no more joy.

Then, suddenly, late yesterday afternoon, it started working. No idea
how or why. I had done nothing special. It was just one more desultory
attempt (connected to one of the direct USB sockets, not to the
powered hub, although I suspect that's irrelevant.) I expected it to
then fail next time I booted/reran. But so far, over several repeat
runs yesterday, it still ran OK. Of course, when I try TODAY, that
might be back to square one again. Go figure...

--
Terry, West Sussex, UK

LinkBack

Thread Tools

Display Modes

« Previous Thread | Next Thread »

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Posting Rules
You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Trackbacks are On Pingbacks are On Refbacks are On

Forum Jump

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Urgent help needed	msbock	Windows Vista Performance & Maintenance	12	06-17-2008 12:03 AM
Urgent Help needed	ANDY	Windows Vista File Management	4	12-16-2007 08:25 AM
URGENT HELP NEEDED	Mark	Windows XP Movie Maker	0	12-24-2003 05:27 PM
Urgent help needed	Lila Freilicher	Mac Office	19	11-19-2003 12:00 AM
Urgent help needed	Scott Moore	Windows XP	2	08-16-2003 03:24 PM