Can't boot up computer with a XFX NVIDIA GeForce 6800 (AGP; 128 MB) when KVM is on the other compute

[ANTant]

Hello! Has anyone experienced this or know why this happens?

I recently installed a new XFX NVIDIA GeForce 6800 (128 MB; AGP;
BIOS v5.40.02.12.08). My computer's refurbished ASUS K8V SE Deluxe
(VIA K8T800 Socket 754 ATX; VIA VT8237 South Bridge; revision 2;
1007 Firmware) will not boot up (not even video card BIOS and
motherboard BIOS) if my Omni Cube 2-ports KVM box switch (PS/2 and
VGA is on the other computer (Linux/Debian box)? I get no beeps or
anything. I do hear the fans spin up. My Samsung SyncMaster 763 MB
CRT monitor's light reported no video signal feed either. Computer
just hangs. Its reset button doesn't work. So, I have to power off
the computer by holding the power button for five seconds or use
the power supply unit's switch. If I leave the KVM on this computer
and turn on the computer, then it will boot up just fine.

I never had this problem with previous video cards (ATI Radeon 9800
All-In-Wonder 128 MB AGP, GeForce2 and 4, etc.). You can read my
full computer setup on
http://alpha.zimage.com/~ant/antfarm/about/computers.txt (primary
one is the one that has this problem). Is there something I missed
in CMOS or something?

Thank you in advance.
--
"An ant is a wise creature for itself, but it is a shrewd thing in an orchard or garden." --Francis Bacon
/\___/\
/ /\ /\ \ Phillip (Ant) @ http://antfarm.ma.cx (Personal Web Site)
| |o o| | Ant's Quality Foraged Links (AQFL): http://aqfl.net
\ _ / Please remove ANT if replying by e-mail.
( )

 

[Paul]

Hello! Has anyone experienced this or know why this happens?

I recently installed a new XFX NVIDIA GeForce 6800 (128 MB; AGP;
BIOS v5.40.02.12.08). My computer's refurbished ASUS K8V SE Deluxe
(VIA K8T800 Socket 754 ATX; VIA VT8237 South Bridge; revision 2;
1007 Firmware) will not boot up (not even video card BIOS and
motherboard BIOS) if my Omni Cube 2-ports KVM box switch (PS/2 and
VGA is on the other computer (Linux/Debian box)? I get no beeps or
anything. I do hear the fans spin up. My Samsung SyncMaster 763 MB
CRT monitor's light reported no video signal feed either. Computer
just hangs. Its reset button doesn't work. So, I have to power off
the computer by holding the power button for five seconds or use
the power supply unit's switch. If I leave the KVM on this computer
and turn on the computer, then it will boot up just fine.

I never had this problem with previous video cards (ATI Radeon 9800
All-In-Wonder 128 MB AGP, GeForce2 and 4, etc.). You can read my
full computer setup on
http://alpha.zimage.com/~ant/antfarm/about/computers.txt (primary
one is the one that has this problem). Is there something I missed
in CMOS or something?

Thank you in advance.

According to this, there is an optional power adapter.

http://web.belkin.com/support/download/files/F1DJ102P-man.pdf

I would try the unit with that power adapter connected. If the
design has diodes to select a powering source, the KVM should
stop drawing power from the PS/2 connector from the computer,
when the 9V 600mA optional power adapter is plugged in.

It is possible the KVM and the motherboard have a chat during POST
when the motherboard tries to initialize the keyboard, and it
could be something during that chat that isn't working. But
that would be a lot harder to debug.

The K8V SE Deluxe has the vocal POST feature, and if you plug
amplified speakers into the green audio connector on the back
of the computer, you might get an audible error message stating
what the problem is (use the motherboard audio connector, even
if you have a sound card plugged in - the vocal POST is hard
wired to the motherboard audio connector). If there is no
audible error message, then something must be happening to the
power on the motherboard. At least a couple of the error messages
from the vocal POST chip can be sent to the green audio connector,
without processor assistance, so you might get further symptoms
by listening to the audio output when you try to start the
K8V SE up.

Just a guess,
Paul

 

[ANTant]

According to this, there is an optional power adapter.

I would try the unit with that power adapter connected. If the
design has diodes to select a powering source, the KVM should
stop drawing power from the PS/2 connector from the computer,
when the 9V 600mA optional power adapter is plugged in.

I could try that, but I found out someone else had similiar problems
without a KVM switch. Hmm!

It is possible the KVM and the motherboard have a chat during POST
when the motherboard tries to initialize the keyboard, and it
could be something during that chat that isn't working. But
that would be a lot harder to debug.

Is keyboard and mouse required? I know in CMOS, one can set to
ignore them. I don't even get to BIOS part. Or does that not
matter?

The K8V SE Deluxe has the vocal POST feature, and if you plug
amplified speakers into the green audio connector on the back
of the computer, you might get an audible error message stating
what the problem is (use the motherboard audio connector, even
if you have a sound card plugged in - the vocal POST is hard
wired to the motherboard audio connector). If there is no
audible error message, then something must be happening to the
power on the motherboard. At least a couple of the error messages
from the vocal POST chip can be sent to the green audio connector,
without processor assistance, so you might get further symptoms
by listening to the audio output when you try to start the
K8V SE up.

I will have to hook that up.
--
"Whenever I see an old lady slip and fall on a wet sidewalk, my first instinct is to laugh. But then I think, what if I was an ant, and she fell on me. Then it wouldn't seem quite so funny." --Saturday Night Live FAQ: Deep Thoughts
/\___/\
/ /\ /\ \ Phillip (Ant) @ http://antfarm.ma.cx (Personal Web Site)
| |o o| | Ant's Quality Foraged Links (AQFL): http://aqfl.net
\ _ / Please remove ANT if replying by e-mail.
( )

 

[Paul]

Is keyboard and mouse required? I know in CMOS, one can set to
ignore them. I don't even get to BIOS part. Or does that not
matter?

My gut tells me this is a power problem, and that is why you might
not get the BIOS or the Vocal POST to run at all, while the Asus
motherboard is connected to the KVM.

If you try to run the Asus motherboard without anything connected
to the PS/2 ports, then you should be able to observe some
response from the BIOS. The Vocal POST should deliver a message
about the missing keyboard, after a wait of perhaps 30 seconds
or longer. That would at least tell you the BIOS was able to
run.

If you look at the datasheet, there isn't a lot to stop the
Vocal POST from working. It looks like as soon as it gets a
source of power, it will start to run the program stored
in the serial ROM connected to the Vocal POST chip. A couple
of the error messages can be delivered without the processor,
but for most of the rest of the messages (like the missing
keyboard message), the processor actually commands the
sending of the message to your amplified speakers.

http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83791SDSGa.pdf

The PS/2 ports on an Asus motherboard are protected by a
Polyfuse. That is a polymeric fuse that opens when it gets
hot, and closes again after it cools off. The fuse is automatic
and never needs to be replaced. Now, what I don't understand,
is why the motherboard cannot boot if that fuse is open. So
I'm not claiming that an overload is a 100% guaranteed root
cause of your symptoms - it just stands out to me, that your
KVM is stealing power from the motherboard, and using the
optional adapter with the KVM should stop it from needing
to steal power.

(Some info on a Polyfuse. If you look near the PS/2 stack on
the motherboard, the Polyfuse should be close by.)

http://www.wickmann.com/products/SMD1812.pdf

So, do some more experiments, and see whether the Vocal POST
is able to run or not.

Paul

 

[ANTant]

Is keyboard and mouse required? I know in CMOS, one can set to

My gut tells me this is a power problem, and that is why you might
not get the BIOS or the Vocal POST to run at all, while the Asus
motherboard is connected to the KVM.

If you try to run the Asus motherboard without anything connected
to the PS/2 ports, then you should be able to observe some
response from the BIOS. The Vocal POST should deliver a message
about the missing keyboard, after a wait of perhaps 30 seconds
or longer. That would at least tell you the BIOS was able to
run.

If you look at the datasheet, there isn't a lot to stop the
Vocal POST from working. It looks like as soon as it gets a
source of power, it will start to run the program stored
in the serial ROM connected to the Vocal POST chip. A couple
of the error messages can be delivered without the processor,
but for most of the rest of the messages (like the missing
keyboard message), the processor actually commands the
sending of the message to your amplified speakers.

The PS/2 ports on an Asus motherboard are protected by a
Polyfuse. That is a polymeric fuse that opens when it gets
hot, and closes again after it cools off. The fuse is automatic
and never needs to be replaced. Now, what I don't understand,
is why the motherboard cannot boot if that fuse is open. So
I'm not claiming that an overload is a 100% guaranteed root
cause of your symptoms - it just stands out to me, that your
KVM is stealing power from the motherboard, and using the
optional adapter with the KVM should stop it from needing
to steal power.

(Some info on a Polyfuse. If you look near the PS/2 stack on
the motherboard, the Polyfuse should be close by.)

So, do some more experiments, and see whether the Vocal POST
is able to run or not.

I doubt it is a power supply issue. Both keyboard and mouse are driven
off the 5v rail. The load that changes the most is the 12v rail which
is the drives spinning up. The 12 and 5 v rail are completely separate
circuits.

This explains why another XFX user had similiar symptoms. He doesn't
even use a KVM.
--
"Whenever I see an old lady slip and fall on a wet sidewalk, my first instinct is to laugh. But then I think, what if I was an ant, and she fell on me. Then it wouldn't seem quite so funny." --Saturday Night Live FAQ: Deep Thoughts
/\___/\
/ /\ /\ \ Phillip (Ant) @ http://antfarm.ma.cx (Personal Web Site)
| |o o| | Ant's Quality Foraged Links (AQFL): http://aqfl.net
\ _ / Please remove ANT if replying by e-mail.
( )

 

[Paul]

I doubt it is a power supply issue. Both keyboard and mouse are driven
off the 5v rail. The load that changes the most is the 12v rail which
is the drives spinning up. The 12 and 5 v rail are completely separate
circuits.

This explains why another XFX user had similiar symptoms. He doesn't
even use a KVM.

I expect we are not talking about the same thing.

The PS/2 ports are powered by a five volt source. There is a header
on the motherboard (KBPWR) that allows the selection of +5V or
+5VSB. The +5VSB supply on an ATX supply is a limited resource,
and if +5VSB was overloaded, that might be enough to shut the computer
off.

After the KBPWR header and before the PS/2 ports, is the Polyfuse
that protects the motherboard against damage. You would think that
if the Polyfuse opens, because the KVM draws too much power from
the PS/2 power pin, that only the KVM would be affected. Perhaps
receiving no response from the PS/2 port is hanging the computer.
Perhaps the motherboard has some way to monitor the voltage
level at the PS/2 port. I'm not sure I can cook up a consistent
theory to explain your results - but I feel the problem has something
to do with the power being drawn through the KBPWR header and the
Polyfuse.

So my focus is more with respect to KBPWR and the Polyfuse
end of things, rather than this having anything to do with the
ATX power supply.

About the only obvious fix I can see for you, is to try the
optional 9V adapter for the KVM.

Paul