Debian 12 PPC64 (MintPPC64), Two Monitors, Only One Being Used

Hi,

My apologies for the repeat of this message. I am resending to make this a unique thread, as requested by Adrian and others.

Adrian, Jeroen, if creating a fresh message with a unique title doesn't make this a unique thread, could you point me at the requirements to do this please? Thanks!

--- repeated post ---

I have a late 2005 Power Mac G5 Quad running Debian 12 PPC64 with the MintPPC64 layer on it. I have two Apple 20" Cinema displays connected to the system via the two DVI ports supplied by my single nVidia GeForce 6600 video card (supported by the "nouveau" driver).

Under Mac OS X (Sorbet) Leopard, both monitors are active and used as one extended desktop. Under Mint/Debian, only one is in use.

I have researched extensively online and tried all sorts of solutions, largely involving xrandr and xset. Nothing has worked so far. xrandr reports two displays, which it names DVI-I-1 and DVI-I-2.

The usual prescription:

xrandar --output DVI-I-2 --auto

is accepted and executed without error, but the monitor stubbornly stays off. Correction: the power light stays on, but the screen stays off.

Constructions like:

xrandr --output DVI-I-1 --auto --output DVI-I-2 --auto --rightof DVI-I-1

also executes without error, but there is no change in the screen... it stays off.

The system understands that there is a second monitor... the mouse cursor will disappear into the second one. If I set it as primary, windows will open on that screen, but because it is off, I can't see them. I have occasionally managed to snag one of them and drag them back to the screen that IS on.

It is as if everything is working logically, but physically, nothing is turning the screen on. The physical screen doesn't seem to be connected to the logical one.

I am stumped at this point.

Any and all pointers much appreciated.

Regards,
Michael