Multiple USB Devices on ASUS

  • Thread starter Thread starter LindaM
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LindaM

Hi All,

I am having an odd problem and don't know if it can be resolved. I
recently built a new machine using ASUS P5G41-M with 4GB RAM, an Intel
Core 2 Duo 3GHz processor, and a 380W PSU, running Windows XP SP3. The
old Machine was an ASUS P5L-VM, with 2GB RAM, an Intel Pentium D
processor, and a 350W PSU, running Windows XP SP3r.

The problem:

I set up the following USB devices on the New PC exactly as I had on
the old PC:

1) USB Wireless Mouse
2) Logitech PC Camera
3) HP Laserjet P2015 Printer
4) HO Officejet 6310 AIO Printer

In addition I have now added:

5) 500GB Seagate External Hard Drive

I set up the Laserjet first and made that my default printer. Then I
set up the Officejet All-In-One printer. The first thing I noticed is
the printer made itself the default printer. I literally watched it
change. Then when I tried to print to either printer neither would
print. If I unplug the device and plug it back in I get the message
"windows doesn't recognize the device" and then ANYTHING I plug into
the USB port is not recognized. And some of my other devices are no
longer recognized.

I finally uninstalled the Officejet and shut down the PC. I actually
unplugged the PC from the power supply and then all my devices were
seen and seemed to be ok. I just cannot add the 2nd printer.

I spoke to an HP rep who insisted that I would never be able to have 2
USB printers hooked up because the new motherboards USB ports use
power differently and therefore I would not be able to have 2 USB
printers hooked up (Mind you both of these printers are USB - no lpt
ports). I find this incredibly hard to believe since the new
motherboards don't even have LPT ports available and EVERYTHING seems
to be going to the USB. What good is having USB devices if you can't
have them all plugged in?

Tell me this guy didn't know what he was talking about and how I can
resolve this issue. And if you're wondering why I have 2 printers, 1
is for black & white fast printing (I run a lot of long jobs here) and
the other is an all-in-one that I can print color, or scan from.

Things I have tried:

I swapped power supplies - same problem
I took the mobo out and put it on a cardboard box to see if there was
a grounding problem - same problem
I ran a Windows Repair - same problem

The only thing that seems to correct, at least while my 4 devices (not
my 2nd printer) the USB not being recognized is shutting down the PC
and unplugging it from the power supply then plugging it back in and
powering back up.

Anyone run into this? If so, has anyone come up with a solution?

Thanks

Linda
 
LindaM said:
Hi All,

I am having an odd problem and don't know if it can be resolved. I
recently built a new machine using ASUS P5G41-M with 4GB RAM, an Intel
Core 2 Duo 3GHz processor, and a 380W PSU, running Windows XP SP3. The
old Machine was an ASUS P5L-VM, with 2GB RAM, an Intel Pentium D
processor, and a 350W PSU, running Windows XP SP3r.

The problem:

I set up the following USB devices on the New PC exactly as I had on
the old PC:

1) USB Wireless Mouse
2) Logitech PC Camera
3) HP Laserjet P2015 Printer
4) HO Officejet 6310 AIO Printer

In addition I have now added:

5) 500GB Seagate External Hard Drive

I set up the Laserjet first and made that my default printer. Then I
set up the Officejet All-In-One printer. The first thing I noticed is
the printer made itself the default printer. I literally watched it
change. Then when I tried to print to either printer neither would
print. If I unplug the device and plug it back in I get the message
"windows doesn't recognize the device" and then ANYTHING I plug into
the USB port is not recognized. And some of my other devices are no
longer recognized.

I finally uninstalled the Officejet and shut down the PC. I actually
unplugged the PC from the power supply and then all my devices were
seen and seemed to be ok. I just cannot add the 2nd printer.

I spoke to an HP rep who insisted that I would never be able to have 2
USB printers hooked up because the new motherboards USB ports use
power differently and therefore I would not be able to have 2 USB
printers hooked up (Mind you both of these printers are USB - no lpt
ports). I find this incredibly hard to believe since the new
motherboards don't even have LPT ports available and EVERYTHING seems
to be going to the USB. What good is having USB devices if you can't
have them all plugged in?

Tell me this guy didn't know what he was talking about and how I can
resolve this issue. And if you're wondering why I have 2 printers, 1
is for black & white fast printing (I run a lot of long jobs here) and
the other is an all-in-one that I can print color, or scan from.

Things I have tried:

I swapped power supplies - same problem
I took the mobo out and put it on a cardboard box to see if there was
a grounding problem - same problem
I ran a Windows Repair - same problem

The only thing that seems to correct, at least while my 4 devices (not
my 2nd printer) the USB not being recognized is shutting down the PC
and unplugging it from the power supply then plugging it back in and
powering back up.

Anyone run into this? If so, has anyone come up with a solution?

Thanks

Linda
Click to expand...

I can't answer your software question, but I can answer your hardware
question.

Asus places Polyfuse devices in the USB path. A single 1.1 amp or
so (self recovering) fuse, is used to power the two USB ports in
a "stack". The USB spec limits power to 0.5 amp (i.e. 500 milliamps)
on each port. So in fact the motherboard is fully capable of powering
500mA loads on each connector. And if you're only drawing heavy
power from one connector, it will even allow a bit of overpower,
before the automatically recovering fuse opens and cuts off power.
The fuse closes, when it cools off.

Your power supply is the other, power limiting device. The
USB ports on a modern motherboard are powered from the +5VSB
power rail. If you read the label on the side of your power
supply, it may say "+5VSB @ 2A" or "+5VSB @ 3A". Those are
maximum current ratings the supply is willing to provide.

Normally, those are not a limitation. For example, there might
be an issue, if you connected four or more USB 2.5" external
hard drives to the computer.

If a printer had no other source of power, but the USB bus,
then it could draw up to 500mA. If the printer plugs
into the wall, then it won't need bus power, and only
a few milliamps will come from the USB port.

A device like an Alcatel USB DSL modem can draw 500mA. Some
of those used to violate the spec, and at 535mA or so,
would cause some computers to shut off the USB port.

If you really are limited by the power distribution scheme,
you can use a self-powered USB hub, to assist in providing
power. But unless you have the specific power-hungry devices,
I think this is a "red herring" issue.

(This USB hub comes with its own power adapter - 5V @ 2A or so.)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817364017

Here, the specification actually verifies the power supply
provided is 5V @ 2A, suitable for up to four USB ports
running at the max 500mA current each. They never provide
power adapters big enough to run all the ports flat out.
I think the biggest I've seen, is a wall adapter for 5V @ 3A
for a USB hub, but they don't make those any more. This size
seems to be common now.

http://www.startech.com/item-specs/ST7202USB-7-Port-USB-20-Hub.aspx

So, yes there are power limits, but the fact we aren't buried in
postings from people with USB power problems, tells you that
most of the time, this isn't an issue.

Older motherboards used to have a jumper on the motherboard, to
select USB powering via +5V or +5VSB, but modern motherboards
no longer support that (convenient) feature. Using +5V eliminates
all concerns about the power supply being the limit, as that rail
can provide 20A or more. The +5VSB rail used now, is a weaker
rail, but for the average person, this is not an issue.

If you're moving backup data between two USB 2.5" drives, chances
are you have enough power to do it. If you have a lot of those
drives hooked up, then there could be trouble. 3.5" external
hard drives, the ones that have a wall adapter, you can use
as many of those as you want. And that is because the wall adapter
is the major source of power.

Paul
 
Hi All,

I am having an odd problem and don't know if it can be resolved. I
recently built a new machine using ASUS P5G41-M with 4GB RAM, an Intel
Core 2 Duo 3GHz processor, and a 380W PSU, running Windows XP SP3. The
old Machine was an ASUS P5L-VM, with 2GB RAM, an Intel Pentium D
processor, and a 350W PSU, running Windows XP SP3r.

The problem:

I set up the following USB devices on the New PC exactly as I had on
the old PC:

1) USB Wireless Mouse
2) Logitech PC Camera
3) HP Laserjet P2015 Printer
4) HO Officejet 6310 AIO Printer

In addition I have now added:

5) 500GB Seagate External Hard Drive

I set up the Laserjet first and made that my default printer. Then I
set up the Officejet All-In-One printer. The first thing I noticed is
the printer made itself the default printer. I literally watched it
change. Then when I tried to print to either printer neither would
print. If I unplug the device and plug it back in I get the message
"windows doesn't recognize the device" and then ANYTHING I plug into
the USB port is not recognized. And some of my other devices are no
longer recognized.

I finally uninstalled the Officejet and shut down the PC. I actually
unplugged the PC from the power supply and then all my devices were
seen and seemed to be ok. I just cannot add the 2nd printer.

I spoke to an HP rep who insisted that I would never be able to have 2
USB printers hooked up because the new motherboards USB ports use
power differently and therefore I would not be able to have 2 USB
printers hooked up (Mind you both of these printers are USB - no lpt
ports). I find this incredibly hard to believe since the new
motherboards don't even have LPT ports available and EVERYTHING seems
to be going to the USB. What good is having USB devices if you can't
have them all plugged in?

Tell me this guy didn't know what he was talking about and how I can
resolve this issue. And if you're wondering why I have 2 printers, 1
is for black & white fast printing (I run a lot of long jobs here) and
the other is an all-in-one that I can print color, or scan from.

Things I have tried:

I swapped power supplies - same problem
I took the mobo out and put it on a cardboard box to see if there was
a grounding problem - same problem
I ran a Windows Repair - same problem

The only thing that seems to correct, at least while my 4 devices (not
my 2nd printer) the USB not being recognized is shutting down the PC
and unplugging it from the power supply then plugging it back in and
powering back up.

Anyone run into this? If so, has anyone come up with a solution?

Thanks

Linda
Click to expand...

It should be noted that motherboard USB ports are "grouped" together.
This is generally known as the "USB root hub." Most of these appear
to share the USB port supplied power over the USB channels. If the
requested power level exceeds the "alloted" power, the entire USB
channel shuts all USB devices on that channel. There does not seem to
be a method of adjusting this. However, you might be able to add more
power to the USB ports by adding a powered USB hub.
 
You can have two usb printers installed at the same time, however you can't
have them both on when you are installing another, turn one off and then
attempt to install the new one, and as the other posters have said, use a
HUB, not the USB ports on the PC directly.
Once they are both installed you can select which one is default.
 
Thank you to all who posted. And Paul, thank you for your detailed
explanation. That really clarified a lot of things for me.

I will try the USB Hub that Paul recommended and I will try shutting
the one printer off when I install the other printer as was suggested
by sgopus. It never occurred to me to shut one of them off.

I will post back if/when I resolve this issue.

Thanks again for all the advice,

LInda
 
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