At my last reboot X started but blacked the screen. When logging into the system remotely all processes seem to be running just fine (e.g. Firefox is automatically started), so X is clearly running, but it is likely just a small switch that tells the screen to go black instead of showing the display.
I have tried removing xorg.conf and get the same result.
The system has an nVidia card and an Intel card. I have so far been using the Intel card, but as long as the drivers for the cards are free software I don't really care which card to use.
How can I get the display working again?
# lshw -C display *-display UNCLAIMED description: VGA compatible controller product: GK107M [GeForce GT 740M] vendor: NVIDIA Corporation physical id: 0 bus info: pci@0000:01:00.0 version: a1 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress vga_controller bus_master cap_list configuration: latency=0 resources: memory:d2000000-d2ffffff memory:a0000000-afffffff memory:b0000000-b1ffffff ioport:4000(size=128) memory:b2000000-b207ffff *-display description: VGA compatible controller product: 3rd Gen Core processor Graphics Controller vendor: Intel Corporation physical id: 2 bus info: pci@0000:00:02.0 version: 09 width: 64 bits clock: 33MHz capabilities: msi pm vga_controller bus_master cap_list rom configuration: driver=i915 latency=0 resources: irq:47 memory:d4000000-d43fffff memory:c0000000-cfffffff ioport:5000(size=64)