DL580 Debian 4.0 Wavy right side of screen

[markwheeler]

I have 2 DL580's: a Gen 1 and Gen 2. Linux is installed on both. Display is fine for G2. Compaq Proliant banner and POST display OK on G1, but when the Linux desktop loads, the left 1/3 of screen is OK but the right 2/3 is a wavy transposed image that is not readable. 2 different monitor give the identical result.

What is wrong with the displayed image? How can I fix it?

[markwheeler]

They are DL380's; not DL580's.

[Matti_Kurkela]

What type of monitor it is (CRT or LCD)?

It sounds like the computers may have been originally configured with a higher-specification monitor (higher maximum resolution and/or refresh rate) than the ones you're using now.

Most Linux distributions, including Debian, configure a set of "virtual consoles" by default. These are accessible using Ctrl-Alt- keystrokes. The standard convention is to have the graphical desktop at Ctrl-Alt-: it automatically becomes the default virtual console when the graphical desktop starts up.

The first six virtual consoles (Ctrl-Alt- to Ctrl-Alt-) normally have a text-mode login prompt. If you select the first virtual console, you may even see the tail end of the boot messages still on screen.

Switch to any of the text-mode virtual consoles, log in and become root. Now you can temporarily shut down the graphical desktop system and reconfigure it:

ls /etc/init.d/?dm
(find out whether the program that manages your graphical login screen is named xdm, kdm, gdm, wdm or something else. I'll assume you're using gdm after this point; substitute as appropriate)

sh /etc/init.d/gdm stop
(This stops the desktop system. This may cause an automatic switch to virtual console 1: if you were using another virtual console, simply use Ctrl-Alt- to return to the one you were using and continue.)

dpkg-reconfigure xserver-xorg
(This is one of the ways to reconfigure the graphics settings. The user interface is fairly self-descriptive.)

sh /etc/init.d/gdm start
(This re-starts the desktop system and automatically switches you to the virtual console 7. Remember to go back to the text-mode console you were using and log out, otherwise you will be offering free root access to anyone who can get at the console and knows something about Linux.)

MK