Analog input cannot display this video mode

[replab_robin]

I have a dell 8400 with a 17" flat panel monitor (1280x1024 75/60Hz). I have a working Kubuntu 7.04 and most things are fine.

During boot up, after the initial splash screen, I see the message

Analog Input: monitor cannot display this video mode I think this is generated by the flatpanel itself. Then the X clock appears and I see the KDE startup proceeding.

I think this is only a problem for the non-console view so I guess i could switch terminals with alt+f1 to see a console, but am not sure. I edited my xorg.conf to eliminate all the modelines except the 1280x1024 ones, but that makes no difference.

I much prefer the behaviour I had with PCBSD (on the same system) where I saw the horrible grey hash screen when X started up; at least I knew things were going on. Interestingly during shutdown the screen goes completely black for a fair time before I start seeing messages.

Is there some way to control the X video mode at startup?

tia

Robin

[SheeEttin]

Re: Analog input cannot display this video mode

Not without some serious digging.
You may want to reconfigure your X server, however. Just run "sudo dpkg-reconfigure xserver-xorg". This will remake your xorg.conf, putting in lines your hardware and monitor support.

[replab_robin]

Re: Analog input cannot display this video mode

But surely I started with the value determined at install time; are you saying that the installer doesn't do Xorg -conf ?

I already saved some changes obtained via xvidtune, I guess I can do what you say, but (K)Ubuntu won't get far if it doesn't actually do the configuration as you suggest.

thanks and I'll give it a go

Robin

[replab_robin]

Re: Analog input cannot display this video mode

Not without some serious digging.
You may want to reconfigure your X server, however. Just run "sudo dpkg-reconfigure xserver-xorg". This will remake your xorg.conf, putting in lines your hardware and monitor support.

I tried the above, but that doesn't fix the unresponsive screen. Tested and find that during the display of the message I cannot switch to a console using ctl+alt+fn.

Just hope nothing goes wrong while this video mode is on.

Robin

[SheeEttin]

Re: Analog input cannot display this video mode

Try setting your video to some resolution you know it will support, e.g. 800x600@60Hz. That's pretty standard.
Also do some research on the hardware, specifically the refresh rates it supports. You may need to specify them manually.

[replab_robin]

Re: Analog input cannot display this video mode

Try setting your video to some resolution you know it will support, e.g. 800x600@60Hz. That's pretty standard.
Also do some research on the hardware, specifically the refresh rates it supports. You may need to specify them manually.

Where exactly should this video resolution setting go? When X finally starts up this message goes away and I get the resolution expected and (one of those specified in xorg.conf). Is there some place that the Xorg startup can be configured to use a specific resolution?

Robin

[SheeEttin]

Re: Analog input cannot display this video mode

Wait, can you clarify this?
You see the splash for the duration of its presence, then it says "cannot display mode", then X and KDE start up and you are able to log in (or you are automatically logged in)?
If that's the case, then I wouldn't worry about it. It's probably just switching resolutions and color depths.

And the keys to switch to a console are Ctrl+Alt+Fx, not Alt+Fx.

[replab_robin]

Re: Analog input cannot display this video mode

Wait, can you clarify this?
You see the splash for the duration of its presence, then it says "cannot display mode", then X and KDE start up and you are able to log in (or you are automatically logged in)?
If that's the case, then I wouldn't worry about it. It's probably just switching resolutions and color depths.

And the keys to switch to a console are Ctrl+Alt+Fx, not Alt+Fx.

yes I see splash a bit of the console flashes by and then the screen goes black with the "cannot display mode" message. After a 20 second pause the screen goes black and I see the X cursor appear, then the KDE session starts normally. I'm fairly sure you're right about this just being some kind of transitional issue, but if anything were to go wrong in that mode I can't switch to a visible console (I tried the ctrl+alt+f1 and see no change). Something must be doing the video mode change and I would like it to switch to the final mode not the incorrect intermediate. I know this is possible, as I previously had PCBSD on the same hardware, and that behaved more sensibly during the kde startup.

Robin

[SheeEttin]

Re: Analog input cannot display this video mode

Well, when KDE comes up, try switching to a console. If it works, the "cannot display mode" just means that it can't display whatever it might be trying to display between resolutions.
If it doesn't, and you don't see a console, then you might be in trouble. This should only be a problem if something bad happens during the switch which causes it to not perform the switch properly, which I don't think is very likely.

[replab_robin]

Re: Analog input cannot display this video mode

Well, when KDE comes up, try switching to a console. If it works, the "cannot display mode" just means that it can't display whatever it might be trying to display between resolutions.
If it doesn't, and you don't see a console, then you might be in trouble. This should only be a problem if something bad happens during the switch which causes it to not perform the switch properly, which I don't think is very likely.

When KDE starts I can switch to a console; I'm not worried about that phase, my worry is that something might go wrong during the 10-20seconds when this message is displayed and I get hung in that situation. It's surely something that ought to be controllable and this itch is bugging me especially since I know it's not required. I always found X startup fairly impossible to track. Something must determine this intermediate mode.

[SheeEttin]

Re: Analog input cannot display this video mode

Well, I don't think that there's too much to go wrong that will cause it to be unable to switch to a console.
On the inability to track the startup process, there is a way to enable the boot log daemon, instructions here (last section) (thanks to UnicornRider). You may have a permissions problem at first, chmod can take care of that. (By the way, it will include all kinds of control codes for the splash screen. I don't recommend viewing in ksystemlog.)

[replab_robin]

Re: Analog input cannot display this video mode

Well, I don't think that there's too much to go wrong that will cause it to be unable to switch to a console.
On the inability to track the startup process, there is a way to enable the boot log daemon, instructions here (last section) (thanks to UnicornRider). You may have a permissions problem at first, chmod can take care of that. (By the way, it will include all kinds of control codes for the splash screen. I don't recommend viewing in ksystemlog.)

you may be right, but if it does fail with the wrong mode then even though the switch may happen I won't be able to see what I'm typing. Thanks for the pointer to the log stuff.