Cannot connect Dell Precision M60 to external monitor

Q I have a Dell Precision M60 running SUSE 10.0. Unfortunately, I (and apparently everyone else posting to Google-able sites) cannot connect to an external monitor. I have tried an older Dell analogue tube monitor, as well as a brand-new Sony KLV-S23A10 flat panel TV with a PC connection. I have tried direct connection (no extension cords) from PC to this monitor as well as to an older analogue unit at work. The laptop uses Fn+F8 to switch between internal and external video; invoking this typically hangs the machine. I've examined the BIOS settings (F2 on boot) and tried both video source settings, System and Dock... I have followed various HOWTOs and examined my xorg.conf, to include adding new Monitor and Display and Screen modules... I have changed my resolution, HSync and Vsync settings to match the acceptable range of the monitor (1280x768, 47.4H and 60V being the recommended values)... No success. A Yast hardware scan does not find the monitor anywhere. A similar unit (Dell Latitude) at work that runs Windows XP is able to find an external monitor without problem, so it must be a problem with the Linux kernel, or at least the SUSE implementation thereof.

A Does trying to switch between the video outputs actually hang the machine, or does it just appear to hang because all output is now going to a non-existent device? If the latter, Fn+F8 should switch back to the internal display. X.org has a way to use two monitor outputs at once, called MergedFB. This can be used in the same way you'd use Xinerama to span a desktop across two monitors, but it also has a 'clone' mode, which puts the same display on both monitors. This is the mode to use when you want to output a laptop's display to a desktop monitor or projector. You'll need to add the following lines to the Device section of /etc/X11/xorg.conf:

Option "MergedFB" "auto"
Option "CRT2Position" "clone"
Option "MetaModes"
"1024x768 800x600 640x480"

The first line saves switching X.org configurations whenever you want to use an external monitor - the system switches to MergedFB if a monitor is detected when X starts. The second line makes the display on the external monitor a clone of the first. The third is a list of supported display modes, so should be the same as the Modes lines in the Screen section. If you don't have any Modes lines, just enter the mode that you usually display at to get you started, provided the external monitor also supports this mode. You may need to set your BIOS to send video both to internal and to external displays. Your Precision laptop uses an ATI Radeon chipset, and I know that the X.org driver for this definitely supports MergedFB as I use it on my iBook. There is a lot more information on setting up and using MergedFB, for cloned or dual-head displays, in the dual-head tutorial at www.winischhofer.at/linuxsispart2.shtml#mergedfbmode.

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