Can't recognize PS/2 and USB at same time

[M.L.]

My friend is having a problem with his Gateway GM5072 WinXP MCE that
he fired up after having sat in his basement for years. The PC is
undamaged and has never been used, but he cannot find the original CDs
for it. The computer fired up OK but it wouldn't recognize any USB
devices although the Device Manager shows all USB controllers, hubs
and devices as working. The USB ports work for drawing power to the
USB speakers. I've done all the following while trying to help.

1.) Checked the BIOS for USB enabling
2.) Uninstalled/Reinstalled USB controllers/hubs/devices entries in
Device Manager
3.) Reinstalled chipset drivers
4.) Unplugged computer for 15 minutes (during which time I looked
inside the PC to check for damage or misconnections)

After that last step I of course had to plug in all peripherals again.
When the PC rebooted it actually started recognizing USB devices.
Unfortunately, it no longer recognized the PS/2 keyboard and PS/2
mouse.

I unplugged the PC for 5 minutes without unplugging the monitor,
modem, speakers, and PS/2 devices. I removed all USB devices.

After rebooting, the PS/2 devices worked again but the USB devices
were again not recognized. We'd like to get the system working as is
before trying to reinstall the OS or install a USB expansion card. Can
someone give us more ideas as to what's wrong with the system? Thanks.

 

[SC Tom]

My friend is having a problem with his Gateway GM5072 WinXP MCE that
he fired up after having sat in his basement for years. The PC is
undamaged and has never been used, but he cannot find the original CDs
for it. The computer fired up OK but it wouldn't recognize any USB
devices although the Device Manager shows all USB controllers, hubs
and devices as working. The USB ports work for drawing power to the
USB speakers. I've done all the following while trying to help.

1.) Checked the BIOS for USB enabling
2.) Uninstalled/Reinstalled USB controllers/hubs/devices entries in
Device Manager
3.) Reinstalled chipset drivers
4.) Unplugged computer for 15 minutes (during which time I looked
inside the PC to check for damage or misconnections)

After that last step I of course had to plug in all peripherals again.
When the PC rebooted it actually started recognizing USB devices.
Unfortunately, it no longer recognized the PS/2 keyboard and PS/2
mouse.

I unplugged the PC for 5 minutes without unplugging the monitor,
modem, speakers, and PS/2 devices. I removed all USB devices.

After rebooting, the PS/2 devices worked again but the USB devices
were again not recognized. We'd like to get the system working as is
before trying to reinstall the OS or install a USB expansion card. Can
someone give us more ideas as to what's wrong with the system? Thanks.

In BIOS, along with USB Enabled, look to see if there's a setting for Legacy
USB Devices. If so, set it as Auto or Enabled if it isn't already.

Did you change the CMOS battery? After so many years, it may be dying/dead.
(Is the time correct on boot up?)

What is the installed XP service pack level?

Try plugging in one peripheral at a time and see what happens instead of all
at once. It could be just one device that's dragging the bus down so that
the rest don't work.

 

[Hot-Text]

My friend is having a problem with his Gateway GM5072 WinXP MCE that
he fired up after having sat in his basement for years. The PC is
undamaged and has never been used, but he cannot find the original CDs
for it. The computer fired up OK but it wouldn't recognize any USB
devices although the Device Manager shows all USB controllers, hubs
and devices as working. The USB ports work for drawing power to the
USB speakers. I've done all the following while trying to help.

1.) Checked the BIOS for USB enabling
2.) Uninstalled/Reinstalled USB controllers/hubs/devices entries in
Device Manager
3.) Reinstalled chipset drivers
4.) Unplugged computer for 15 minutes (during which time I looked
inside the PC to check for damage or misconnections)

After that last step I of course had to plug in all peripherals again.
When the PC rebooted it actually started recognizing USB devices.
Unfortunately, it no longer recognized the PS/2 keyboard and PS/2
mouse.

I unplugged the PC for 5 minutes without unplugging the monitor,
modem, speakers, and PS/2 devices. I removed all USB devices.

After rebooting, the PS/2 devices worked again but the USB devices
were again not recognized. We'd like to get the system working as is
before trying to reinstall the OS or install a USB expansion card. Can
someone give us more ideas as to what's wrong with the system? Thanks.

Motherboard Driver NVIDIA 50.09 10.6 MB 07/23/2010
< http://support.gateway.com/us/en/product/default.aspx?tab=1&modelId=2691 >
< http://support.gateway.com/s/SOFTWARE/Medialess//MLXPH2/MLXPH2asi.shtml >

 

[M.L.]

In BIOS, along with USB Enabled, look to see if there's a setting for Legacy
USB Devices. If so, set it as Auto or Enabled if it isn't already.

Thanks for your reply. We already checked that BIOS USB was enabled,
as well as legacy. But I'll be checking again anyway in case I forgot
something.

Did you change the CMOS battery? After so many years, it may be dying/dead.
(Is the time correct on boot up?)

No, the time was off by years. I reset it to current but I'll check
back to see if the time is staying current.

What is the installed XP service pack level?

SP2. I know it needs updating but the service pack version shouldn't
cause the USB ports to stop working.

Try plugging in one peripheral at a time and see what happens instead of all
at once. It could be just one device that's dragging the bus down so that
the rest don't work.

We tried restarting with various USB devices plugged in or not. They
weren't working.

 

[glee]

Thanks for your reply. We already checked that BIOS USB was enabled,
as well as legacy. But I'll be checking again anyway in case I forgot
something.


No, the time was off by years. I reset it to current but I'll check
back to see if the time is staying current.


SP2. I know it needs updating but the service pack version shouldn't
cause the USB ports to stop working.


We tried restarting with various USB devices plugged in or not. They
weren't working.

WHAT specific USB devices are you talking about.... what are you trying
to plug in that is not detected? Also, which USB ports are you using?

You are using the term "recognize".... do you actually mean "detect"?
When you plug in a USB device, is there no detection activity at all?
"Recognize" implies that it may be detected but not finding drivers....
"Detect" implies no reaction whatsoever to the device being plugged in.

 

[Hot-Text]

Thanks but I'm pretty certain that's the chipset driver we installed.

To be certain you::
Need to know the hardware on your system to choose the right driver?
Download Hardware Vendor Detection Utility

You Need to read::
Media Center User Guide Gateway 1.0 567.8 KB 01/03/2011


Chipset driver is the installation software for the USB devices too..
To reinstalling the Chipset driver will fix all driver,
for USB ports and the Fire-Wire port.

 

[M.L.]

In BIOS, along with USB Enabled, look to see if there's a setting for Legacy
USB Devices. If so, set it as Auto or Enabled if it isn't already.

Did you change the CMOS battery? After so many years, it may be dying/dead.
(Is the time correct on boot up?)

That notion sounds intriguing. The time was years off initially so on
my next visit I'll check to see if it's current.

What is the installed XP service pack level?

Try plugging in one peripheral at a time and see what happens instead of all
at once. It could be just one device that's dragging the bus down so that
the rest don't work.

That's a good and very likely possibility of the source.

Thanks to all who replied. I can't thank all responders personally but
I want everyone to know that I'm grateful for their contributions.

My friend went to a tech shop and was told that one USB port is good.
So they sold him an external 4-port USB hub (for $24.00) to resolve
that issue.

Unfortunately his command of computers and the English language are so
weak that it would be fruitless for me to try to walk him through the
process of connecting a USB hub over the phone. So I'll visit him this
Saturday to set him up. I hope the tech made the right diagnosis.

 

[Paul]

That notion sounds intriguing. The time was years off initially so on
my next visit I'll check to see if it's current.


That's a good and very likely possibility of the source.

Thanks to all who replied. I can't thank all responders personally but
I want everyone to know that I'm grateful for their contributions.

My friend went to a tech shop and was told that one USB port is good.
So they sold him an external 4-port USB hub (for $24.00) to resolve
that issue.

Unfortunately his command of computers and the English language are so
weak that it would be fruitless for me to try to walk him through the
process of connecting a USB hub over the phone. So I'll visit him this
Saturday to set him up. I hope the tech made the right diagnosis.

One other part to USB and PS/2 ports, is they're fuse protected.

The fuse type is "Polyfuse", which is a polymer fuse. On overcurrent,
the fuse melts and stops conducting. When the fuse cools off, the
polymer solidifies again, and begins to conduct current again.
The fuse can cycle over and over again. They've been known to fail
completely, but there aren't too many reports of that in the
news groups.

By being a reusable device, there's no nuisance "driving to the store
to buy a replacement". That's why they use them. The trip point on
those, is set well above the normal current (or, at least that's the
design recommendation).

The normal allocation, is one Polyfuse per stack of two USB ports.
And one Polyfuse for the PS/2 pair. The Parallel Port (if one is present),
can be in on the fuse thing as well.

it's possible for a motherboard to mix the loads together. The worst
I've seen, is a cheap motherboard using one fuse for the whole works.
Which is a pretty cheesy way to go, but gives more useful symptoms
when it opens (as the set of things that fail at the same time, would
be relatively unique).

I didn't think this was that good a match for your symptoms, so
just keep this one filed away for another day.

Paul

 

[M.L.]

That notion sounds intriguing. The time was years off initially so on
my next visit I'll check to see if it's current.

Bingo!!! I went back today and found that the time/date were off after
I reset it last week. After a new CMOS battery was installed all 7 of
the USB ports worked. Thanks to everyone for their contribution.

 

[Paul]

Bingo!!! I went back today and found that the time/date were off after
I reset it last week. After a new CMOS battery was installed all 7 of
the USB ports worked. Thanks to everyone for their contribution.

So the mechanism there would be, settings stored in the 256 byte
CMOS RAM, were lost between sessions. For that to happen, another
ingredient is the user switching off power at the back of the computer.

The CMOS battery lasts for around 3 years, if AC power is not applied.

If you have the computer plugged in, and the switch on the back is in
the ON position, the chipset gets +5VSB as a power source. And then
the CR2032 coin cell will last longer than 3 years. As long as the
ATX power supply, provides some power, nothing flows out of the
CR2032 while that condition exists. The CR2032 doesn't ever "charge up",
but things are set up, that if the ATX supply gives +5VSB, then the
CR2032 isn't used.

The CMOS RAM stores BIOS settings. Some settings are stored in standard
locations, others are whatever the BIOS designer wants to do. Occasionally,
other software interferes with the unofficial locations. And the RAM itself,
is inside the Southbridge, in the CMOS well, an area of silicon separated
by transmission gates. That's how the well can be powered, without the
power leaking out and powering the rest of the Southbridge. It's like
a separate portion of the silicon die in the Southbridge, that can be
run on an isolated power source.

The parts in there, include the RTC (real time clock, the thing you noted
was running slow). That works almost exactly like a digital watch, and
the time source runs at a lowly 32KHz. Just like your digital watch does.
The other part is the CMOS RAM. They both run off a 3V source, and begin
to misbehave at voltages as low as 2V. Since there is a Schottky diode
in the path as well, the CMOS battery must be at least 2.3V or so, to
maintain CMOS RAM values and keep the clock running, when the computer
is unplugged.

I understand the USB has disable settings (settings which could be in
the CMOS RAM, and corrupted on low battery), but does the PS/2 as well ?
I wouldn't have thought those would ever be turned off. The BIOS on
the machines I have here, they don't like it if you try to run without
a PS/2 keyboard (on a PS/2 based machine). You need to at least use the
"Halt On No Error" setting to do that. And the BIOS really doesn't like it,
if you plug a PS/2 mouse in the PS/2 keyboard hole, or vice versa

Paul

 

[Paul]

If it's really a Schottky diode, the diode drop won't be 0.7V (that's for
Si), but more like 0.2 or 0.3 V.

(actually for Si diodes, it's more like 0.6V to 0.7V typically, depending on
the current going through it; with low currents, the drop would probably be
closer to 0.6V)

CR2032 ----- BAT54C ---- Southbridge_CMOS_Well__VBAT
2.3V (0.3V drop) (Needs minimum of 2.0V)

So the minimum acceptable voltage at the CR2032 terminals, is 2.3V.

When the battery is fresh, it provides slightly more than 3.0V.

You can run the battery down from 3.0V to 2.3V, over the
course of three years of "unplugged PC", and the time should
still be right.

Paul