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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
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