The driver can't find any displays connected:
(--) Jun 07 12:49:48 NVIDIA(0): Connected display device(s) on Quadro NVS 420 at PCI:3:0:0:
(--) Jun 07 12:49:48 NVIDIA(0): none
(EE) Jun 07 12:49:48 NVIDIA(0): No display devices found for this X screen.
(II) UnloadModule: "nvidia"
(II) UnloadModule: "ramdac"
(II) UnloadModule: "wfb"
(II) UnloadModule: "fb"
(EE) Screen(s) found, but none have a usable configuration.
Fatal server error:
no screens found
Note that the NVS 420 has two GPUs on a single board. (You can see both GPUs by looking at lspci.) You only have one GPU configured in xorg.conf. Try the following:
- Configure both GPUs in xorg.conf by running `nvidia-xconfig -a` as root.
- If that doesn't work, try plugging in more monitors, if possible, or changing the connector the monitor is plugged into.
Are you sure the fan is stopping completely? It might just be spinning at a slower speed. Until the driver is loaded, the fan will spin at maximum speed. Once the driver is loaded, it will slow down to an appropriate speed based on the current temperature.