No display signal after monitor upgrade

[Dominio]

I recently upgraded my (very) old monitor with a new TFT Samsung SyncMaster (model 931BF). After the upgrade, however, the monitor would lose the signal completely whenever the X system would startup in Kubuntu. The bootup logo and progress bar would be displayed just fine, but when the KDE login screen should appear the screen would go blank as if disconnected from the computer, and go into power saving mode after a while.

The monitor works fine when I run windows, this only happens when I boot my Kubuntu partition. I have tried running x-configure once, but that did not resolve the problem. The same thing also happens if I try to boot from the Edgy Eft installation DVD to perform a full upgrade (I currently have Dapper Drake installed).

[penguin.ch]

Re: No display signal after monitor upgrade

One way "out" would be to make use of a (live) system completely unrelated to the Ubuntu breed and with good hardware recognition, as for example Knoppix.

Once this were (dis-)playing well, you could try to transfer the relevant sections of this system's X server configuration to your own.

[Dominio]

Re: No display signal after monitor upgrade

Good idea. I'm familiar with KNOPPIX. What would these "relevant sections" of the X configuration be, though? Just xorg.conf?

Thanks for the suggestion.

[penguin.ch]

Re: No display signal after monitor upgrade

What would these "relevant sections" of the X configuration be, though? Just xorg.conf?

Not even that; merely the parts related to monitor and screen (display), respectively, should answer your purpose ... of course, you could also copy the file as a whole and "fine-tune" it.

But please make sure beforehand that the configuration that the graphic card driver your new configuration in going to point to will be available ... "Knoppix is not Ubuntu is not Debian".

[Dominio]

Re: No display signal after monitor upgrade

Amazingly enough, I get the same problem even when booting from a KNOPPIX 5.1.1 Live DVD. I think it's time to bring this matter to Samsung's hardware support. Thanks for the help, anyway.

[penguin.ch]

Re: No display signal after monitor upgrade

Amazingly enough, I get the same problem even when booting from a KNOPPIX 5.1.1 Live DVD

Not a complete surprise - the X server setup is similiar (read: equally bad), containing so-called modlines, which may or may not work (further reading).

To verify this my assumption, you may try to boot (into) a "complete different" (live) system, as for example Puppy Linux. If this worked, I'd recommend to manually (re-) configure Kubuntu's X server ...

[Dominio]

Re: No display signal after monitor upgrade

I finally managed to fix the problem. I had connected my monitor to my computer using only the digital advanced video cable, and it seems the X server is not able to send any video signal through the video card's digital port. When I also connected the standard analog video cable between the monitor and the computer, at least the analog signal would be received from the X server, and the monitor would automatically switch between analog and digital receiving modes as needed to get the signal. So finally I have a working Kubuntu system again. Thanks for the help.