Monitor detected by the system, but it is not displaying

I’ve been having issues with a monitor when booting up Manjaro. I have two monitors, and they both work perfectly fine on Windows and during booting. However, when Manjaro is booted, one monitor states “no signal” and then sleeps. It is a Dell D2015HF that is plugged into a VGA to DVI converter. I’ve tried adding “amdgpu.dc=0” to my grub, and it does fix the one problematic monitor, but this causes the other working monitor (that uses hdmi) to then not work. What might be the problem here?


  Kernel: 5.8.16-2-MANJARO x86_64 bits: 64 compiler: N/A 
  parameters: BOOT_IMAGE=/boot/vmlinuz-5.8-x86_64 
  root=UUID=9f3b4142-4868-426f-b0bf-483cdf720a67 rw quiet apparmor=1 
  security=apparmor resume=UUID=63140814-0368-43af-bcf7-3f6f7d24d6a9 
  Desktop: Xfce 4.14.2 tk: Gtk 3.24.20 info: xfce4-panel wm: bspwm 0.9.10 
  dm: LightDM 1.30.0 Distro: Manjaro Linux 
  Type: Desktop Mobo: ASRock model: H97 Pro4 serial: <filter> 
  UEFI: American Megatrends v: P1.90 date: 07/27/2015 
  Topology: Quad Core model: Intel Core i7-4790K bits: 64 type: MT MCP 
  arch: Haswell family: 6 model-id: 3C (60) stepping: 3 microcode: 28 
  L2 cache: 8192 KiB 
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx 
  bogomips: 63879 
  Speed: 1690 MHz min/max: 800/4400 MHz Core speeds (MHz): 1: 834 2: 1150 
  3: 1290 4: 817 5: 1091 6: 1140 7: 868 8: 1040 
  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 
  Device-1: AMD Tonga PRO [Radeon R9 285/380] vendor: XFX Pine driver: amdgpu 
  v: kernel bus ID: 01:00.0 chip ID: 1002:6939 
  Display: x11 server: X.Org 1.20.9 driver: amdgpu,ati unloaded: modesetting 
  alternate: fbdev,vesa display ID: :0.0 screens: 1 
  Screen-1: 0 s-res: 1920x1080 s-dpi: 96 s-size: 508x286mm (20.0x11.3") 
  s-diag: 583mm (23") 
  Monitor-1: HDMI-A-0 res: 1920x1080 hz: 60 dpi: 55 
  size: 880x490mm (34.6x19.3") diag: 1007mm (39.7") 
  Monitor-2: DVI-D-1 res: 1920x1080 hz: 60 dpi: 112 
  size: 435x239mm (17.1x9.4") diag: 496mm (19.5") 
  OpenGL: renderer: AMD Radeon R9 380 Series (TONGA DRM 3.38.0 
  5.8.16-2-MANJARO LLVM 10.0.1) 
  v: 4.6 Mesa 20.1.8 direct render: Yes 
  Device-1: Intel 9 Series Family HD Audio vendor: ASRock 
  driver: snd_hda_intel v: kernel bus ID: 00:1b.0 chip ID: 8086:8ca0 
  Device-2: AMD Tonga HDMI Audio [Radeon R9 285/380] vendor: XFX Pine 
  driver: snd_hda_intel v: kernel bus ID: 01:00.1 chip ID: 1002:aad8 
  Device-3: Samson C01U condenser microphone type: USB driver: snd-usb-audio 
  bus ID: 2-4:4 chip ID: 17a0:0001 
  Sound Server: ALSA v: k5.8.16-2-MANJARO 
  Device-1: Intel Ethernet I218-V vendor: ASRock driver: e1000e v: 3.2.6-k 
  port: f040 bus ID: 00:19.0 chip ID: 8086:15a1 
  IF: enp0s25 state: down mac: <filter> 
  Device-2: Intel Wireless 8260 driver: iwlwifi v: kernel port: e000 
  bus ID: 03:00.0 chip ID: 8086:24f3 
  IF: wlp3s0 state: up mac: <filter> 
  Local Storage: total: 1.02 TiB used: 7.78 GiB (0.7%) 
  SMART Message: Required tool smartctl not installed. Check --recommends 
  ID-1: /dev/sda vendor: Western Digital model: WD10EZEX-00BN5A0 
  size: 931.51 GiB block size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s 
  rotation: 7200 rpm serial: <filter> rev: 1A01 scheme: GPT 
  ID-2: /dev/sdb vendor: Crucial model: CT120BX100SSD1 size: 111.79 GiB 
  block size: physical: 512 B logical: 512 B speed: 6.0 Gb/s serial: <filter> 
  rev: MU02 scheme: GPT 
  ID-1: / raw size: 94.36 GiB size: 92.38 GiB (97.90%) used: 7.78 GiB (8.4%) 
  fs: ext4 dev: /dev/sdb2 
  Kernel: swappiness: 60 (default) cache pressure: 100 (default) 
  ID-1: swap-1 type: partition size: 17.13 GiB used: 0 KiB (0.0%) priority: -2 
  dev: /dev/sdb3 
  System Temperatures: cpu: 41.0 C mobo: N/A gpu: amdgpu temp: 46 C 
  Fan Speeds (RPM): N/A gpu: amdgpu fan: 1663 
  Processes: 259 Uptime: 2m Memory: 15.57 GiB used: 1.74 GiB (11.2%) 
  Init: systemd v: 246 Compilers: gcc: 10.2.0 Packages: pacman: 1085 lib: 315 
  flatpak: 0 Shell: Bash v: 5.0.18 running in: xfce4-terminal inxi: 3.1.05 

1 Like

:+1: Welcome to Manjaro! :+1:


Most of the passive adapters (I wouldn’t call them “converters”) exhibit this behaviour, so the solution becomes:

  • look if yours has Linux drivers.
  • Replace it by an active converter (100€+, they generally come with their own power supply and internal DSP)
  • Replace it with a passive converter, not an adapter that is certified Linux compatible.


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Does using dvi-d to dvi-d cause problem?

  1. that’s just an extension cable, so unless the cable is damaged, no it shouldn’t.
  2. Posting with another question in a thread is discouraged here.

:man_shrugging: :sob:

I thought it was related

Bt sorry

@Computer_Email23 No worries: we live and we learn… :wink:

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I’m not too familiar with converters certified with Linux – is it possible that you could explain to me where and how I would find these?

I’ve been searching a few websites and googling, but I don’t seem to be able to find much information on vga-dvi converters and their compatibility with Linux.

I was also wondering if you may be able to expand on why amdgpu.dc=0 (seeming to disable DC) causes the monitor to suddenly work. This wouldn’t be as big of an issue if I were using just the one monitor, but disabling DC would cause me to not be able to use my HDMI monitor along with it.

Thank you for the assistance!

Yes, it takes a bit of digging and I found this one

I don’t know. where did I say that?


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I was referring to this here from the original post:

You didn’t bring it up specifically – I was just wondering if it was something you may also know – sorry for the confusion there!

:man_shrugging: :sob:


Okay well thanks for the help regardless! I appreciate it a lot and you’ve been really helpful with finding converters and what to look for and whatnot!

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