No display on tv with hdmi from laptop

I’m trying to hook up my spare laptop running Manjaro KDE to my living room tv. It’s an older Toshiba satellite amd-a6. When I plug it into the avr or tv directly via hdmi, display manager sees it but nothing displays on the tv. I tried with Linux Mint and its working fine, same with my other laptop running Win10.

Can be anything

could you first provide the output of

inxi -Fazy

can be you need to install it first.

pamac install inxi

copy the output and paste it here

select the text and click </> on the topbar

  Kernel: 5.8.6-1-MANJARO x86_64 bits: 64 compiler: N/A 
  parameters: BOOT_IMAGE=/boot/vmlinuz-5.8-x86_64 
  root=UUID=078e2227-1315-4af2-87f7-770ca464845c rw quiet apparmor=1 
  security=apparmor udev.log_priority=3 
  Desktop: KDE Plasma 5.19.5 tk: Qt 5.15.0 wm: kwin_x11 dm: SDDM 
  Distro: Manjaro Linux 
  Type: Laptop System: TOSHIBA product: Satellite C40D-A v: PSCDSC-008003 
  serial: <filter> 
  Mobo: AMD model: Larne serial: <filter> UEFI: Insyde v: 1.20 
  date: 05/31/2013 
  ID-1: BAT1 charge: 53.1 Wh condition: 53.1/47.5 Wh (112%) volts: 12.5/10.8 
  model: Panasonic PA5109U-1BRS type: Li-ion serial: N/A status: Full 
  cycles: 28 
  Device-1: hidpp_battery_0 model: Logitech Wireless Touch Keyboard K400 Plus 
  serial: <filter> charge: 100% (should be ignored) rechargeable: yes 
  status: Discharging 
  Topology: Quad Core model: AMD A6-5200 APU with Radeon HD Graphics bits: 64 
  type: MCP arch: Jaguar family: 16 (22) model-id: N/A stepping: 1 
  microcode: 700010F L2 cache: 2048 KiB 
  flags: avx lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm 
  bogomips: 15979 
  Speed: 1996 MHz min/max: 800/2000 MHz Core speeds (MHz): 1: 1996 2: 1996 
  3: 1996 4: 1996 
  Vulnerabilities: Type: itlb_multihit status: Not affected 
  Type: l1tf status: Not affected 
  Type: mds status: Not affected 
  Type: meltdown status: Not affected 
  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 AMD retpoline, STIBP: disabled, RSB filling 
  Type: srbds status: Not affected 
  Type: tsx_async_abort status: Not affected 
  Device-1: AMD Kabini [Radeon HD 8400 / R3 Series] vendor: Toshiba 
  driver: radeon v: kernel alternate: amdgpu bus ID: 00:01.0 
  chip ID: 1002:9830 
  Device-2: Suyin TOSHIBA Web Camera - HD type: USB driver: uvcvideo 
  bus ID: 2-3:2 chip ID: 064e:e375 serial: <filter> 
  Display: x11 server: X.Org 1.20.8 compositor: kwin_x11 driver: radeon 
  FAILED: ati unloaded: modesetting alternate: fbdev,vesa display ID: :0 
  screens: 1 
  Screen-1: 0 s-res: 1920x1080 s-dpi: 96 s-size: 507x285mm (20.0x11.2") 
  s-diag: 582mm (22.9") 
  Monitor-1: HDMI-0 res: 1920x1080 dpi: 30 size: 1650x928mm (65.0x36.5") 
  diag: 1893mm (74.5") 
  OpenGL: renderer: AMD KABINI (DRM 2.50.0 5.8.6-1-MANJARO LLVM 10.0.1) 
  v: 4.5 Mesa 20.1.7 direct render: Yes 
  Device-1: AMD Kabini HDMI/DP Audio driver: snd_hda_intel v: kernel 
  bus ID: 00:01.1 chip ID: 1002:9840 
  Device-2: AMD FCH Azalia vendor: Toshiba driver: snd_hda_intel v: kernel 
  bus ID: 00:14.2 chip ID: 1022:780d 
  Sound Server: ALSA v: k5.8.6-1-MANJARO 
  Device-1: Qualcomm Atheros AR8162 Fast Ethernet vendor: Toshiba driver: alx 
  v: kernel port: 3000 bus ID: 01:00.0 chip ID: 1969:1090 
  IF: enp1s0 state: up speed: 100 Mbps duplex: full mac: <filter> 
  Device-2: Realtek RTL8188EE Wireless Network Adapter driver: rtl8188ee 
  v: kernel port: 2000 bus ID: 05:00.0 chip ID: 10ec:8179 
  IF: wlp5s0 state: down mac: <filter> 
  Local Storage: total: 698.64 GiB used: 7.64 GiB (1.1%) 
  SMART Message: Unable to run smartctl. Root privileges required. 
  ID-1: /dev/sda vendor: Toshiba model: MQ01ABD075 size: 698.64 GiB 
  block size: physical: 512 B logical: 512 B speed: 3.0 Gb/s 
  rotation: 5400 rpm serial: <filter> rev: 4M scheme: GPT 
  ID-1: / raw size: 698.34 GiB size: 686.38 GiB (98.29%) used: 7.64 GiB (1.1%) 
  fs: ext4 dev: /dev/sda2 
  Alert: No Swap data was found. 
  System Temperatures: cpu: 61.2 C mobo: N/A gpu: radeon temp: 59 C 
  Fan Speeds (RPM): N/A 
  Processes: 168 Uptime: 6m Memory: 5.25 GiB used: 1.16 GiB (22.0%) 
  Init: systemd v: 246 Compilers: gcc: N/A Packages: pacman: 1156 lib: 315 
  flatpak: 0 Shell: Bash v: 5.0.18 running in: konsole inxi: 3.1.05

So it seems to work when I have the laptop lid closed and only the tv on. Its a 4k tv but i use 1080p but it only allows 30fps. On mint I was able to use 120hz.

As you can see in the dispay section it says that it failes to load you display driver

Display: x11 server: X.Org 1.20.8 compositor: kwin_x11 driver: radeon
FAILED: ati unloaded: modesetting alternate: fbdev,vesa display ID: :0 screens:1
OpenGL: renderer: AMD KABINI (DRM 2.50.0 5.8.6-1-MANJARO LLVM 10.0.1)
v: 4.5 Mesa 20.1.7 direct render: Yes

I guess your running with amdgpu now but I think you need to set a few thing to get it in its best.

Since it is a sea island classified card I think you could modify the kernel parameters in the kernel command line as.

radeon.cik_support=0 amdgpu.cik_support=1

This way you force the amdgpu drivers to load.

The way to do that is open /etc/default/grub with your favorite editor with sudo.
For instance:

sudo vim /etc/default/grub

find the line that starts with

GRUB_CMDLINE_LINUX_DEFAULT="quiet udev.log_priority=3"

modify it to

GRUB_CMDLINE_LINUX_DEFAULT="quiet radeon.cik_support=0 amdgpu.cik_support=1 udev.log_priority=3"

safe the new config en rebuild grub with

sudo grub-mkconfig -o /boot/grub/grub.cfg


check how it goes now

Note: It can be you also need to tune some xorg settings.