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Only one of the three USB ports work

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Anonymous
a b B Homebuilt system
April 4, 2005 4:25:47 PM

Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

My Toshiba Satellite 1405-S151 laptop has three USB ports. My Logitec
optical mouse will only work (move the screen cursor) when plugged into
the center port. If I plug it into either of the other two, the mouse
will light up red when moved, but the cursor doesn't move. So all three
ports are getting power.

The built-in touchpad works properly at all times.

In Device Manager, if I expand the Universal Serial Bus controllers
category, there are two items: One instance of AliPCI to UBS Open Host
Controller and one instance of USB Root Hub. No yellow exclamation marks.

I've been using the laptop for deejaying for almost three years. While
unlikely, it is conceivable that I've always plugged the mouse into the
same port every time (over 300 times), so I can't say for certain that
all three ports once worked.

Operating system is XP, Home Edition. No other devices - not even a
printer - are connected to the laptop.

Questions:

1. When a motherboard has more than one USB port, are they all wired in
parallel, that is, without isolation resistors (or other components)
between each?

2. Should Device Manager show a Root Hub for each USB port, or will one
instance of Root Hub serve all ports? (My desktop has three instances of
Root Hub and three instances of Host Controller to serve four
motherboard USB connectors.)

3. Any other ideas as to why just one port works?

Thanks for your assistance.

Ray

More about : usb ports work

Anonymous
a b B Homebuilt system
April 4, 2005 4:25:48 PM

Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

Ray K wrote:

> My Toshiba Satellite 1405-S151 laptop has three USB ports.
> My Logitec optical mouse will only work (move the screen
> cursor) when plugged into the center port.

> In Device Manager, if I expand the Universal Serial Bus controllers
> category, there are two items: One instance of AliPCI to UBS Open
Host
> Controller and one instance of USB Root Hub. No yellow exclamation
marks.

> 1. When a motherboard has more than one USB port, are they all
> wired in parallel, that is, without isolation resistors (or
> other components) between each?

They were each separate on the NEC-based USB 2.0 card that I checked
and the schematic provided by NEC.

> 2. Should Device Manager show a Root Hub for each USB port,
> or will one instance of Root Hub serve all ports? (My
> desktop has three instances of Root Hub and three
> instances of Host Controller to serve four motherboard
> USB connectors.)

In my computer I get one Root Hub for each pair of USB ports, and I
have two USB 1.1 ports built into the mobo and four USB 2.0 ports on a
PCI card.

When my NEC-based USB 2.0 card blew one of its two ports, its tiny
power controller chip failed. At the National Semiconductor website,
they said that each USB port needed pretty good capacitors across its
+5V and ground lines to absorb the surge of current that occurred when
something was plugged in, and my USB card's capacitors weren't as good
or as big as those recommended by National.

Two great websites about USB are www.usbman.com and
www.everythingusb.com
Anonymous
a b B Homebuilt system
April 4, 2005 6:16:16 PM

Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

Thanks for the comments on your experience and the other leads.

Ray]


larry moe 'n curly wrote:

> Ray K wrote:
>
>
>>My Toshiba Satellite 1405-S151 laptop has three USB ports.
>>My Logitec optical mouse will only work (move the screen
>>cursor) when plugged into the center port.
>
>
>>In Device Manager, if I expand the Universal Serial Bus controllers
>>category, there are two items: One instance of AliPCI to UBS Open
>
> Host
>
>>Controller and one instance of USB Root Hub. No yellow exclamation
>
> marks.
>
>
>>1. When a motherboard has more than one USB port, are they all
>>wired in parallel, that is, without isolation resistors (or
>>other components) between each?
>
>
> They were each separate on the NEC-based USB 2.0 card that I checked
> and the schematic provided by NEC.
>
>
>>2. Should Device Manager show a Root Hub for each USB port,
>>or will one instance of Root Hub serve all ports? (My
>>desktop has three instances of Root Hub and three
>>instances of Host Controller to serve four motherboard
>>USB connectors.)
>
>
> In my computer I get one Root Hub for each pair of USB ports, and I
> have two USB 1.1 ports built into the mobo and four USB 2.0 ports on a
> PCI card.
>
> When my NEC-based USB 2.0 card blew one of its two ports, its tiny
> power controller chip failed. At the National Semiconductor website,
> they said that each USB port needed pretty good capacitors across its
> +5V and ground lines to absorb the surge of current that occurred when
> something was plugged in, and my USB card's capacitors weren't as good
> or as big as those recommended by National.
>
> Two great websites about USB are www.usbman.com and
> www.everythingusb.com
>
Anonymous
a b B Homebuilt system
April 4, 2005 9:29:36 PM

Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

Ray K wrote:

>
> 2. Should Device Manager show a Root Hub for each USB port, or will one
> instance of Root Hub serve all ports? (My desktop has three instances of
> Root Hub and three instances of Host Controller to serve four
> motherboard USB connectors.)

Actually, there are six USB connectors on my desktop. I forgot about the
two on the front panel.
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