Booting without monitor connected - no more video output afterwards?

[BertieBigBollox]

Running Windows 2000 workstation SP4 on a single card PC.

If I boot with monitor connected, it all works fine.

However, if I boot with no monitor connected, wait for it to boot,
then connected the monitor cable, I get no signal on the monitor.

Weird thing is if I subsequently power off, connect the monitor and
boot it still wont work. Only solution then is to reinstall the
machine.

Its as if the booting with no monitor is knackering things, as if its
switching the machine into a different mode or something.

BTW. I can boot into Safe mode though at all times.

 

[Dave Patrick]

Possibly a bad cable. What are you trying to accomplish?


--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect

 

[Pegasus \(MVP\)]

Running Windows 2000 workstation SP4 on a single card PC.

If I boot with monitor connected, it all works fine.

However, if I boot with no monitor connected, wait for it to boot,
then connected the monitor cable, I get no signal on the monitor.

Weird thing is if I subsequently power off, connect the monitor and
boot it still wont work. Only solution then is to reinstall the
machine.

Its as if the booting with no monitor is knackering things, as if its
switching the machine into a different mode or something.

BTW. I can boot into Safe mode though at all times.

I suspect that booting without a monitor causes Windows to select a display
mode that is incompatible with your monitor. Re-installing Windows is one
way to resolve the issue, selecting a basic display mode (e.g. 800x600)
while in Safe Mode is another.

 

[BertieBigBollox]

Possibly a bad cable. What are you trying to accomplish?

--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]http://www.microsoft.com/protect

Running Windows 2000 workstation SP4 on a single card PC.

If I boot with monitor connected, it all works fine.

However, if I boot with no monitor connected, wait for it to boot,
then connected the monitor cable, I get no signal on the monitor.

Weird thing is if I subsequently power off, connect the monitor and
boot it still wont work. Only solution then is to reinstall the
machine.

Its as if the booting with no monitor is knackering things, as if its
switching the machine into a different mode or something.

BTW. I can boot into Safe mode though at all times.- Hide quoted text -

- Show quoted text -

Not bad cable. Tried two different monitors with different cables.

Our 'system' consists of a number of machines, with just one monitor
which is plugged into one machine at a time, so we need the machines
to boot ok without monitor attached.

 

[BertieBigBollox]

I suspect that booting without a monitor causes Windows to select a display
mode that is incompatible with your monitor. Re-installing Windows is one
way to resolve the issue, selecting a basic display mode (e.g. 800x600)
while in Safe Mode is another.

Yes. I was thinking it was something like this too.

Only use 1024x? anyway though.

 

[Sid Elbow]

However, if I boot with no monitor connected, wait for it to boot,
then connected the monitor cable, I get no signal on the monitor.

You don't say what kind of monitor but connecting a crt monitor while
the system is powered used to be considered a no-no. There were a couple
of reasons postulated .... one that the video card needed the monitor
attached to correctly detect the monitor and configure itself
appropriately .... also that connecting the monitor under power could
physically damage the video card and/or monitor.

I don't know whether either of these effects is postulated for LCD monitors.

 

[BertieBigBollox]

You don't say what kind of monitor but connecting a crt monitor while
the system is powered used to be considered a no-no. There were a couple
of reasons postulated .... one that the video card needed the monitor
attached to correctly detect the monitor and configure itself
appropriately .... also that connecting the monitor under power could
physically damage the video card and/or monitor.

I don't know whether either of these effects is postulated for LCD monitors.

TFT monitor.

 

[Pegasus \(MVP\)]

You don't say what kind of monitor but connecting a crt monitor while the
system is powered used to be considered a no-no. There were a couple of
reasons postulated .... one that the video card needed the monitor
attached to correctly detect the monitor and configure itself
appropriately .... also that connecting the monitor under power could
physically damage the video card and/or monitor.

I don't know whether either of these effects is postulated for LCD
monitors.

I read what you write but during the past 20 years of working with PCs, I've
never experienced any problems when plugging monitors in or out while the
system is powered up.

 

[richard]

Running Windows 2000 workstation SP4 on a single card PC.

If I boot with monitor connected, it all works fine.

However, if I boot with no monitor connected, wait for it to boot,
then connected the monitor cable, I get no signal on the monitor.

Weird thing is if I subsequently power off, connect the monitor and
boot it still wont work. Only solution then is to reinstall the
machine.

Its as if the booting with no monitor is knackering things, as if its
switching the machine into a different mode or something.

BTW. I can boot into Safe mode though at all times.

I suspect corrupted or missing drivers.
Once in safe mode, go through device manager and check for errors.

Might also be something as simple as a cracked cable.
Also check and make sure the plugs are properly seated.

 

[Sid Elbow]

I read what you write but during the past 20 years of working with PCs, I've
never experienced any problems when plugging monitors in or out while the
system is powered up.

Yes, I've (unintentionally) done it too without a problem. I usually
avoid it on the general principle that mating/unmating any live
connector is best avoided.

(And bad things can happen. I was a mechanical engineer working on a
communications satellite years ago. We had just completed a bunch of
powered checkout tests and were a bit behind schedule when a technician
pulled a DB-25 connector before the satellite was fully powered down.
The grounded shell of the connector hit one of the connector pins and
blew out the slip rings buried in the geometric centre of the spacecraft!)

In the case of monitors, I'm pretty sure it was the standard warning in
ATI video card manuals at one time. I think it was concerned with
properly detecting the monitor and not, accidentally, getting into an
operating region that would overdrive the monitor circuitry. It's also
going back a few years and the devices may be better protected these days.

 

[Pennywise]

Running Windows 2000 workstation SP4 on a single card PC.

If I boot with monitor connected, it all works fine.

However, if I boot with no monitor connected, wait for it to boot,
then connected the monitor cable, I get no signal on the monitor.

Weird thing is if I subsequently power off, connect the monitor and
boot it still wont work. Only solution then is to reinstall the
machine.

Its as if the booting with no monitor is knackering things, as if its
switching the machine into a different mode or something.

BTW. I can boot into Safe mode though at all times.

Except for that last sentence, I thought it might be the BIOS. Might
check it out anyhow.

The BIOS might be set to automatically select a mode (analog for
example). If nothing is connected, it might make a bad decision. Might
check out the BIOS settings. >Just a guess<.

 

[Dave Patrick]

You'll want to get yourself a KVM switch. Depending on the hardware it may
turn off the video output when nothing is connected.



--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect


Not bad cable. Tried two different monitors with different cables.

Our 'system' consists of a number of machines, with just one monitor
which is plugged into one machine at a time, so we need the machines
to boot ok without monitor attached.

 

[Dave Patrick]

Yes, I've never had an issue either and generally don't worry about it.



--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect

 

[BertieBigBollox]

I read what you write but during the past 20 years of working with PCs, I've
never experienced any problems when plugging monitors in or out while the
system is powered up.

Nor me !!!!!!

Since found out also that if you leave it in highest resolution mode,
it works OK.

However, if you change it to 1024x768 and then boot without monitor
connected, it seems to screw it up.

It appears that the monitor is reporting problems with 'out of range'

 

[BertieBigBollox]

I suspect corrupted or missing drivers.
Once in safe mode, go through device manager and check for errors.

Might also be something as simple as a cracked cable.
Also check and make sure the plugs are properly seated.- Hide quoted text-

- Show quoted text -

Nah. Installed drivers multiple times. Like I said also, tried several
monitors/cables etc.

 

[BertieBigBollox]

You'll want to get yourself a KVM switch. Depending on the hardware it may
turn off the video output when nothing is connected.

No can do a KVM. These machines are single card machines in a chassis
built for a specific application and, as such, there is no room for
an additional KVM. It is however, a pity that the original designer
choose the swapping cable method rather than use a KVM.

 

[Pegasus \(MVP\)]

I read what you write but during the past 20 years of working with PCs,
I've
never experienced any problems when plugging monitors in or out while the
system is powered up.

Nor me !!!!!!

Since found out also that if you leave it in highest resolution mode,
it works OK.

However, if you change it to 1024x768 and then boot without monitor
connected, it seems to screw it up.

It appears that the monitor is reporting problems with 'out of range'

=================

Your report confirms my initial suspicion: That your graphics adapter
assumes a display mode that is incompatible with your monitor. You could
resolve the problem by freezing the display mode. Here are a few thoughts:
- If you can locate the place in the registry where the display settings are
kept then you could set the security settings such that only you (but not
the "System" account!) can change them.
- You could launch a batch file at startup time that restores the registry
settings to the desired values. The new values would become effective at the
next boot time.
- You could launch a startup macro that changes the display settings back to
what they should be, using something like AutoIt
(http://www.autoitscript.com/autoit3/downloads.shtml). You may need to delay
this macro for a minute or so until things have settled down.

 

[BertieBigBollox]

Nor me !!!!!!

Since found out also that if you leave it in highest resolution mode,
it works OK.

However, if you change it to 1024x768 and then boot without monitor
connected, it seems to screw it up.

It appears that the monitor is reporting problems with 'out of range'

=================

Your report confirms my initial suspicion: That your graphics adapter
assumes a display mode that is incompatible with your monitor. You could
resolve the problem by freezing the display mode. Here are a few thoughts:
- If you can locate the place in the registry where the display settings are
kept then you could set the security settings such that only you (but not
the "System" account!) can change them.
- You could launch a batch file at startup time that restores the registry
settings to the desired values. The new values would become effective at the
next boot time.
- You could launch a startup macro that changes the display settings backto
what they should be, using something like AutoIt
(http://www.autoitscript.com/autoit3/downloads.shtml). You may need to delay
this macro for a minute or so until things have settled down.- Hide quoted text -

- Show quoted text -

Pegasus,

Thx. That makes sense.

Next thing is to try and find where in the registry !!!!

 

[BertieBigBollox]

Supplier of card has got back to me now. They are saying that it is
switching to another output because no monitor is connected. Seems to
make sense.

CTRL-ALT-F1 switches it back on. Trouble is you need to log in blind
first before you can do this....

We have found a sort of workaround using an older driver (v4.1.0.704)
and removing the lvds.sys file.