I have a new Lenovo Thinkbook with GTX1650 graphics. I want to be able to close the lid and use my external HP LP2475 screen (1920x1200 native mode) as the primary display. Running Debian 11 (unstable “Sid”), installed just this morning, I get a perfect display on the laptop screen but nothing on the external monitor (as in “black all the time”; most of the similar threads on here describe momentary flashes, ability to move mouse pointer in there, etc).
Completely opposite to this, the “Nvidia X Server Settings” application displays information about the HP LP2475 monitor (HDMI-1-0 on GPU 0), but not the very laptop screen that it’s displaying on, which seems very odd.
lspci shows both devices
lspci | grep VGA 00:02.0 VGA compatible controller: Intel Corporation CometLake-H GT2 [UHD Graphics] (rev 05) 01:00.0 VGA compatible controller: NVIDIA Corporation TU117M [GeForce GTX 1650 Ti Mobile] (rev a1)
xrandr sees it as a provider
xrandr --listproviders Providers: number : 2 Provider 0: id: 0x43 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 3 outputs: 1 associated providers: 0 name:modesetting Provider 1: id: 0x25f cap: 0x2, Sink Output crtcs: 4 outputs: 1 associated providers: 0 name:NVIDIA-G0
… but it doesn’t see it as a connected display
xrandr | grep connected eDP-1 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
The external monitor is in Xorg.0.log, though there’s an error there which I can’t work out what to do about.
grep HP /var/log/Xorg.0.log [ 29445.381] (--) NVIDIA(GPU-0): HP LP2475w (DFP-0): connected [ 29445.381] (--) NVIDIA(GPU-0): HP LP2475w (DFP-0): Internal TMDS [ 29445.381] (--) NVIDIA(GPU-0): HP LP2475w (DFP-0): 600.0 MHz maximum pixel clock [ 29445.558] (WW) NVIDIA(G0): Cannot find size of first mode for HP LP2475w (DFP-0); cannot [ 29445.558] (WW) NVIDIA(G0): compute DPI from HP LP2475w (DFP-0)'s EDID.
Can someone help me with sorting this out? This new laptop is marvellous compared to its 11-year-old predecessor, but I can’t use it until I get the external monitor working.