HDMI Recognized but External Monitor Blank

I’m on kernel 5.10 and for whatever reason my external monitor stopped working. It shows up fine in xrandr, and I can even connect it and move my mouse or windows into it, so it functions as if the display exists. However, the display is completely blank. I’ve read a bunch of other similar threads, but nothing I try seems to change anything. The display works fine in Windows, and even works in an earlier (I think 4.4) kernel I have installed. Here is some more info:

$ inxi -Faz
tput: unknown terminal "rxvt-unicode-256color"
tput: unknown terminal "rxvt-unicode-256color"
Argument "" isn't numeric in numeric eq (==) at /usr/bin/inxi line 433.
System:
  Kernel: 5.10.19-1-MANJARO x86_64 bits: 64 compiler: gcc v: 10.2.0 
  parameters: BOOT_IMAGE=/boot/vmlinuz-5.10-x86_64 
  root=UUID=a6a0dc76-c0e4-4e3d-af4a-67010bf6518d rw quiet apparmor=1 
  security=apparmor udev.log_priority=3 nouveau.modeset=0 
  Desktop: i3 4.19.1 info: polybar vt: 7 dm: LightDM 1.30.0 
  Distro: Manjaro Linux base: Arch Linux 
Machine:
  Type: Laptop System: Acer product: Aspire E5-575G v: V1.04 
  serial: <filter> 
  Mobo: Acer model: Ironman_SK v: V1.04 serial: <filter> UEFI: Insyde 
  v: 1.04 date: 04/26/2016 
Battery:
  ID-1: BAT1 charge: 33.2 Wh (100.0%) condition: 33.2/62.2 Wh (53.3%) 
  volts: 12.7 min: 11.1 model: PANASONIC AS16B5J type: Li-ion 
  serial: <filter> status: Full 
  Device-1: hidpp_battery_0 model: Logitech Performance MX serial: <filter> 
  charge: 70% (should be ignored) rechargeable: yes status: Discharging 
CPU:
  Info: Dual Core model: Intel Core i5-6200U bits: 64 type: MT MCP 
  arch: Skylake family: 6 model-id: 4E (78) stepping: 3 microcode: E2 cache: 
  L2: 3 MiB 
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx 
  bogomips: 19204 
  Speed: 500 MHz min/max: 400/2800 MHz Core speeds (MHz): 1: 500 2: 500 
  3: 500 4: 500 
  Vulnerabilities: Type: itlb_multihit status: KVM: VMX disabled 
  Type: l1tf 
  mitigation: PTE Inversion; VMX: conditional cache flushes, SMT vulnerable 
  Type: mds mitigation: Clear CPU buffers; SMT vulnerable 
  Type: meltdown mitigation: PTI 
  Type: spec_store_bypass 
  mitigation: Speculative Store Bypass disabled via prctl and seccomp 
  Type: spectre_v1 
  mitigation: usercopy/swapgs barriers and __user pointer sanitization 
  Type: spectre_v2 mitigation: Full generic retpoline, IBPB: conditional, 
  IBRS_FW, STIBP: conditional, RSB filling 
  Type: srbds mitigation: Microcode 
  Type: tsx_async_abort status: Not affected 
Graphics:
  Device-1: Intel Skylake GT2 [HD Graphics 520] 
  vendor: Acer Incorporated ALI driver: i915 v: kernel bus-ID: 00:02.0 
  chip-ID: 8086:1916 class-ID: 0300 
  Device-2: NVIDIA GM107 [GeForce 940MX] driver: N/A 
  alternate: nouveau, nvidia_drm, nvidia bus-ID: 01:00.0 chip-ID: 10de:179c 
  class-ID: 0302 
  Device-3: Realtek HD WebCam type: USB driver: uvcvideo bus-ID: 1-7:7 
  chip-ID: 0bda:57f3 class-ID: 0e02 serial: <filter> 
  Display: x11 server: X.Org 1.20.10 compositor: picom v: git-dac85 driver: 
  loaded: intel unloaded: nvidia display-ID: :0 screens: 1 
  Screen-1: 0 s-res: 1920x1080 s-dpi: 97 s-size: 505x284mm (19.9x11.2") 
  s-diag: 579mm (22.8") 
  Monitor-1: eDP1 res: 1920x1080 dpi: 143 size: 340x190mm (13.4x7.5") 
  diag: 389mm (15.3") 
  OpenGL: renderer: Mesa Intel HD Graphics 520 (SKL GT2) v: 4.6 Mesa 20.3.4 
  direct render: Yes 
Audio:
  Device-1: Intel Sunrise Point-LP HD Audio vendor: Acer Incorporated ALI 
  driver: snd_hda_intel v: kernel alternate: snd_soc_skl bus-ID: 00:1f.3 
  chip-ID: 8086:9d70 class-ID: 0403 
  Device-2: NVIDIA GM107 High Definition Audio [GeForce 940MX] 
  driver: snd_hda_intel v: kernel bus-ID: 01:00.1 chip-ID: 10de:0fbc 
  class-ID: 0403 
  Device-3: Plantronics Plantronics C325-M type: USB 
  driver: plantronics,snd-usb-audio,usbhid bus-ID: 1-2.4.1:6 
  chip-ID: 047f:c029 class-ID: 0300 serial: <filter> 
  Sound Server-1: ALSA v: k5.10.19-1-MANJARO running: yes 
  Sound Server-2: sndio v: N/A running: no 
  Sound Server-3: JACK v: 1.9.17 running: no 
  Sound Server-4: PulseAudio v: 14.2 running: yes 
  Sound Server-5: PipeWire v: 0.3.22 running: no 
Network:
  Device-1: Qualcomm Atheros QCA9377 802.11ac Wireless Network Adapter 
  vendor: Lite-On driver: ath10k_pci v: kernel port: 5040 bus-ID: 03:00.0 
  chip-ID: 168c:0042 class-ID: 0280 
  IF: wlp3s0 state: up mac: <filter> 
  Device-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
  vendor: Acer Incorporated ALI Acer Aspire E5-575G driver: r8169 v: kernel 
  port: 3000 bus-ID: 04:00.1 chip-ID: 10ec:8168 class-ID: 0200 
  IF: enp4s0f1 state: down mac: <filter> 
Bluetooth:
  Device-1: Lite-On Qualcomm Atheros QCA9377 Bluetooth type: USB 
  driver: btusb v: 0.8 bus-ID: 1-5:5 chip-ID: 04ca:3015 class-ID: e001 
  Report: This feature requires one of these tools: hciconfig/bt-adapter 
Drives:
  Local Storage: total: 238.47 GiB used: 74.89 GiB (31.4%) 
  SMART Message: Required tool smartctl not installed. Check --recommends 
  ID-1: /dev/sda maj-min: 8:0 vendor: Kingston model: RBU-SNS8152S3256GG2 
  size: 238.47 GiB block-size: physical: 512 B logical: 512 B 
  speed: 6.0 Gb/s rotation: SSD serial: <filter> rev: 01.R scheme: GPT 
Partition:
  ID-1: / raw-size: 83.81 GiB size: 81.99 GiB (97.83%) 
  used: 74.84 GiB (91.3%) fs: ext4 dev: /dev/sda5 maj-min: 8:5 
  ID-2: /boot/efi raw-size: 100 MiB size: 96 MiB (96.00%) 
  used: 55.1 MiB (57.4%) fs: vfat dev: /dev/sda1 maj-min: 8:1 
Swap:
  Alert: No Swap data was found. 
Sensors:
  System Temperatures: cpu: 35.0 C mobo: N/A 
  Fan Speeds (RPM): N/A 
Info:
  Processes: 164 Uptime: 7m wakeups: 3 Memory: 7.65 GiB 
  used: 1.6 GiB (20.9%) Init: systemd v: 247 tool: systemctl Compilers: 
  gcc: 10.2.0 Packages: apt: 0 pacman: 1630 lib: 459 Shell: Bash v: 5.1.0 
  running-in: urxvt inxi: 3.3.02 
$ sudo mhwd -li
[sudo] password for adam: 
> Installed PCI configs:
--------------------------------------------------------------------------------
                  NAME               VERSION          FREEDRIVER           TYPE
--------------------------------------------------------------------------------
video-hybrid-intel-nvidia-390xx-bumblebee            2020.11.30               false            PCI
           video-linux            2018.05.04                true            PCI
     video-modesetting            2020.01.13                true            PCI


Warning: No installed USB configs!

Why are you running 5.10 then? Some older hardware needs older kernels and that’s just fine and why Manjaro supports so many kernels.

:thinking:

For more information, please read this:

Especially the section on kernels.

:+1:

To find the reason you need to look through the pacman log, chances are you did install or upgrade something kernel / driver related. Nothing happens out of blue. Another possible cause could be alterations to files located in /etc/X11, /etc/modprobe.d, /etc/bumblebee. If you’re sure you didn’t touch them, then you should blame updates.