Monitor detected by the system, but it is not displaying

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1

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?

inxi:

System:
  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 
  udev.log_priority=3 
  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 
Machine:
  Type: Desktop Mobo: ASRock model: H97 Pro4 serial: <filter> 
  UEFI: American Megatrends v: P1.90 date: 07/27/2015 
CPU:
  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 
Graphics:
  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 
Audio:
  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 
Network:
  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> 
Drives:
  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 
Partition:
  ID-1: / raw size: 94.36 GiB size: 92.38 GiB (97.90%) used: 7.78 GiB (8.4%) 
  fs: ext4 dev: /dev/sdb2 
Swap:
  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 
Sensors:
  System Temperatures: cpu: 41.0 C mobo: N/A gpu: amdgpu temp: 46 C 
  Fan Speeds (RPM): N/A gpu: amdgpu fan: 1663 
Info:
  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
2

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

This:

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.

:sob:

1 Like
3

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

4
  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:

5

I thought it was related

Bt sorry

6

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

1 Like
7

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!

8

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

I don’t know. where did I say that?

:+1:

1 Like
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@Fabby

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!

10

:man_shrugging: :sob:

11

@Fabby

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!

1 Like
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