Hi guys,
after this topic has been split out of the original, I will give more context to my problem.
This is a Manjaro KDE edition install and I guess this specific one has been installed with 20.x something, if not 19. I have only very few customizations, and none to the base system, just in the GUI. I mainly use Plasma X11, but have tried the Wayland Session from time to time to see the state of affairs.
This last round of updates (21.1.0 → 21.1.1) broke my sddm and plasma session. System boots up with a blank screen and mouse cursor. I can switch to a tty.
journalctl -b0 -p4 reveals an error for sddm-greeter: Could not find the Qt platform plugin „xcb obs“ in „“
I did try to get obs to work last week but was unsuccessful with screencapture in a wayland session. I did not change anything, I just installed one obs plugin that was supposed to make it work with waylan. Everything worked, even after reboots.
I tried uninstalling obs, but this did not help. I don’t even know if the current sddm or plasma problem stems from obs, I just assumed due to the error message above.
I setup ssh so I can easily access logs and stuff from outside to post here if needed.
I also stopped sddm and tried to start a manual plasma session, either wayland or xorg. both do not start up as they used to.
Any idea/help welcome 
EDIT: As adviced I am updating with system information:
inxi --admin --verbosity=7 --filter --no-host --width
System:
Kernel: 5.13.12-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0
parameters: BOOT_IMAGE=/vmlinuz-5.13-x86_64
root=UUID=b7a1223e-c31d-42b9-866e-e07dade54bce rw quiet apparmor=1
security=apparmor resume=UUID=4b8fcfa2-ea30-44ee-b932-b8b6b466dc67
udev.log_priority=3
Console: tty pts/0 DM: SDDM Distro: Manjaro Linux base: Arch Linux
Machine:
Type: Desktop System: Gigabyte product: Z390 GAMING X v: N/A serial: N/A
Mobo: Gigabyte model: Z390 GAMING X-CF v: x.x serial: N/A
UEFI: American Megatrends v: F10i date: 01/19/2021
Battery:
Message: No system battery data found. Is one present?
Memory:
RAM: total: 31.29 GiB used: 766.6 MiB (2.4%)
Array-1: capacity: 64 GiB slots: 4 EC: None max-module-size: 16 GiB
note: est.
Device-1: ChannelA-DIMM0 size: 8 GiB speed: 3200 MT/s type: DDR4
detail: synchronous bus-width: 64 bits total: 64 bits manufacturer: G.Skill
part-no: F4-3200C16-8GVKB serial: N/A
Device-2: ChannelA-DIMM1 size: 8 GiB speed: 3200 MT/s type: DDR4
detail: synchronous bus-width: 64 bits total: 64 bits manufacturer: G.Skill
part-no: F4-3200C16-8GVKB serial: N/A
Device-3: ChannelB-DIMM0 size: 8 GiB speed: 3200 MT/s type: DDR4
detail: synchronous bus-width: 64 bits total: 64 bits manufacturer: G.Skill
part-no: F4-3200C16-8GVKB serial: N/A
Device-4: ChannelB-DIMM1 size: 8 GiB speed: 3200 MT/s type: DDR4
detail: synchronous bus-width: 64 bits total: 64 bits manufacturer: G.Skill
part-no: F4-3200C16-8GVKB serial: N/A
CPU:
Info: 8-Core model: Intel Core i7-9700K socket: LGA1151 (U3E1) note: check
bits: 64 type: MCP arch: Kaby Lake note: check family: 6 model-id: 9E (158)
stepping: D (13) microcode: EA cache: L1: 512 KiB L2: 12 MiB L3: 12 MiB
bogomips: 57616
Speed: 800 MHz min/max: 800/4900 MHz base/boost: 4600/8300 volts: 1.2 V
ext-clock: 100 MHz Core speeds (MHz): 1: 800 2: 800 3: 800 4: 800 5: 800
6: 800 7: 800 8: 800
Flags: 3dnowprefetch abm acpi adx aes aperfmperf apic arat arch_capabilities
arch_perfmon art avx avx2 bmi1 bmi2 bts clflush clflushopt cmov constant_tsc
cpuid cpuid_fault cx16 cx8 de ds_cpl dtes64 dtherm dts ept ept_ad erms est
f16c flexpriority flush_l1d fma fpu fsgsbase fxsr ht hwp hwp_act_window
hwp_epp hwp_notify ibpb ibrs ibrs_enhanced ida intel_pt invpcid
invpcid_single lahf_lm lm mca mce md_clear mmx monitor movbe mpx msr mtrr
nonstop_tsc nopl nx pae pat pbe pcid pclmulqdq pdcm pdpe1gb pebs pge pln pni
popcnt pse pse36 pts rdrand rdseed rdtscp rep_good sdbg sep smap smep smx ss
ssbd sse sse2 sse4_1 sse4_2 ssse3 stibp syscall tm tm2 tpr_shadow tsc
tsc_adjust tsc_deadline_timer vme vmx vnmi vpid x2apic xgetbv1 xsave xsavec
xsaveopt xsaves xtopology xtpr
Vulnerabilities: Type: itlb_multihit status: KVM: VMX disabled
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: Enhanced IBRS, IBPB: conditional, RSB filling
Type: srbds mitigation: TSX disabled
Type: tsx_async_abort mitigation: TSX disabled
Graphics:
Device-1: AMD Navi 10 [Radeon RX 5600 OEM/5600 XT / 5700/5700 XT]
vendor: Sapphire Limited driver: amdgpu v: kernel bus-ID: 03:00.0
chip-ID: 1002:731f class-ID: 0300
Device-2: Lenovo 500 RGB Camera type: USB driver: uvcvideo bus-ID: 1-2:3
chip-ID: 17ef:482f class-ID: 0e02 serial: <filter>
Display: server: X.org 1.20.13 driver: loaded: amdgpu,ati
unloaded: modesetting,radeon alternate: fbdev,vesa tty: 152x37
Message: Advanced graphics data unavailable in console for root.
Audio:
Device-1: Intel Cannon Lake PCH cAVS vendor: Gigabyte driver: snd_hda_intel
v: kernel alternate: snd_soc_skl,snd_sof_pci_intel_cnl bus-ID: 00:1f.3
chip-ID: 8086:a348 class-ID: 0403
Device-2: AMD Navi 10 HDMI Audio driver: snd_hda_intel v: kernel
bus-ID: 03:00.1 chip-ID: 1002:ab38 class-ID: 0403
Sound Server-1: ALSA v: k5.13.12-1-MANJARO running: yes
Sound Server-2: JACK v: 1.9.19 running: no
Sound Server-3: PulseAudio v: 15.0 running: no
Sound Server-4: PipeWire v: 0.3.33 running: no
Network:
Device-1: Intel Ethernet I219-V vendor: Gigabyte driver: e1000e v: kernel
port: efa0 bus-ID: 00:1f.6 chip-ID: 8086:15bc class-ID: 0200
IF: eno1 state: up speed: 1000 Mbps duplex: full mac: <filter>
IP v4: <filter> type: dynamic noprefixroute scope: global
broadcast: <filter>
IP v6: <filter> type: dynamic noprefixroute scope: global
IP v6: <filter> type: noprefixroute scope: link
Device-2: Broadcom BCM43602 802.11ac Wireless LAN SoC vendor: Apple
driver: brcmfmac v: kernel port: 3000 bus-ID: 06:00.0 chip-ID: 14e4:43ba
class-ID: 0280
IF: wlp6s0 state: down mac: <filter>
WAN IP: <filter>
Bluetooth:
Device-1: Apple Bluetooth Host Controller type: USB
driver: btusb,hid-generic,usbhid bus-ID: 1-12:7 chip-ID: 05ac:8290
class-ID: fe01
Report: bt-adapter ID: hci0 rfk-id: 1 state: down
bt-service: enabled,running rfk-block: hardware: no software: no
address: <filter>
Logical:
Message: No logical block device data found.
RAID:
Message: No RAID data found.
Drives:
Local Storage: total: 3.64 TiB used: 172.25 GiB (4.6%)
ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Samsung
model: SSD 970 EVO Plus 500GB size: 465.76 GiB block-size: physical: 512 B
logical: 512 B speed: 31.6 Gb/s lanes: 4 type: SSD serial: <filter>
rev: 2B2QEXM7 temp: 41.9 C scheme: GPT
SMART: yes health: PASSED on: 343d 23h cycles: 2,693
read-units: 19,533,212 [10.0 TB] written-units: 14,549,447 [7.44 TB]
ID-2: /dev/nvme1n1 maj-min: 259:1 vendor: Samsung
model: SSD 970 EVO Plus 500GB size: 465.76 GiB block-size: physical: 512 B
logical: 512 B speed: 31.6 Gb/s lanes: 4 type: SSD serial: <filter>
rev: 2B2QEXM7 temp: 43.9 C scheme: GPT
SMART: yes health: PASSED on: 263d 15h cycles: 2,706
read-units: 27,444,962 [14.0 TB] written-units: 7,996,501 [4.09 TB]
ID-3: /dev/sda maj-min: 8:0 vendor: Crucial model: CT2000MX500SSD1
family: Micron Client SSDs size: 1.82 TiB block-size: physical: 4096 B
logical: 512 B sata: 3.3 speed: 6.0 Gb/s type: SSD serial: <filter> rev: 023
temp: 33 C scheme: GPT
SMART: yes state: enabled health: PASSED on: 371d 22h cycles: 2666
written: 15.44 TiB
ID-4: /dev/sdb maj-min: 8:16 vendor: Crucial model: CT1000MX500SSD1
family: Micron Client SSDs size: 931.51 GiB block-size: physical: 4096 B
logical: 512 B sata: 3.3 speed: 6.0 Gb/s type: SSD serial: <filter> rev: 033
temp: 32 C scheme: GPT
SMART: yes state: enabled health: PASSED on: 182d 1h cycles: 1105
written: 4.21 TiB
Message: No optical or floppy data found.
Partition:
ID-1: / raw-size: 244.14 GiB size: 239.31 GiB (98.02%)
used: 172.19 GiB (72.0%) fs: ext4 block-size: 4096 B dev: /dev/sdb4
maj-min: 8:20 label: N/A uuid: b7a1223e-c31d-42b9-866e-e07dade54bce
ID-2: /boot raw-size: 1024 MiB size: 975.9 MiB (95.30%)
used: 63.5 MiB (6.5%) fs: ext4 block-size: 4096 B dev: /dev/sdb2
maj-min: 8:18 label: N/A uuid: c1bf9228-b7ac-4044-a466-ff273d643336
ID-3: /boot/efi raw-size: 300 MiB size: 299.4 MiB (99.80%)
used: 344 KiB (0.1%) fs: vfat block-size: 512 B dev: /dev/sdb1 maj-min: 8:17
label: N/A uuid: 22C9-F4C2
Swap:
Kernel: swappiness: 60 (default) cache-pressure: 100 (default)
ID-1: swap-1 type: partition size: 8 GiB used: 0 KiB (0.0%) priority: -2
dev: /dev/sdb3 maj-min: 8:19 label: N/A
uuid: 4b8fcfa2-ea30-44ee-b932-b8b6b466dc67
Unmounted:
ID-1: /dev/nvme0n1p1 maj-min: 259:2 size: 100 MiB fs: vfat label: SYSTEM
uuid: 50CC-B6EE
ID-2: /dev/nvme0n1p2 maj-min: 259:5 size: 128 MiB fs: N/A label: N/A
uuid: N/A
ID-3: /dev/nvme0n1p3 maj-min: 259:6 size: 464.9 GiB fs: ntfs label: Windows
uuid: 4E38CED738CEBCE9
ID-4: /dev/nvme0n1p4 maj-min: 259:7 size: 650 MiB fs: ntfs
label: Recovery image uuid: D2C0CF11C0CEFAAD
ID-5: /dev/nvme1n1p1 maj-min: 259:3 size: 200 MiB fs: vfat label: EFI
uuid: 67E3-17ED
ID-6: /dev/nvme1n1p2 maj-min: 259:4 size: 465.57 GiB fs: apfs label: N/A
uuid: d70e6a0b-517d-4008-96fa-ad4c7056d840
ID-7: /dev/sda1 maj-min: 8:1 size: 200 MiB fs: vfat label: EFI
uuid: 67E3-17ED
ID-8: /dev/sda2 maj-min: 8:2 size: 1.36 TiB fs: apfs label: N/A
uuid: d1866be0-3b7b-41d5-87eb-54f4b4062f33
ID-9: /dev/sda3 maj-min: 8:3 size: 465.54 GiB fs: ntfs label: WindowsData
uuid: 54985531985512BA
ID-10: /dev/sdb5 maj-min: 8:21 size: 678.08 GiB fs: ntfs label: Gaming
uuid: 1040C41E40C40C82
USB:
Hub-1: 1-0:1 info: Full speed (or root) Hub ports: 16 rev: 2.0
speed: 480 Mb/s chip-ID: 1d6b:0002 class-ID: 0900
Hub-2: 1-1:2 info: VIA Labs VL812 Hub ports: 4 rev: 2.1 speed: 480 Mb/s
chip-ID: 2109:2812 class-ID: 0900
Device-1: 1-2:3 info: Lenovo 500 RGB Camera type: Video driver: uvcvideo
interfaces: 4 rev: 2.0 speed: 480 Mb/s power: 500mA chip-ID: 17ef:482f
class-ID: 0e02 serial: <filter>
Device-2: 1-9:4 info: Logitech Unifying Receiver type: Keyboard,Mouse,HID
driver: logitech-djreceiver,usbhid interfaces: 3 rev: 2.0 speed: 12 Mb/s
power: 98mA chip-ID: 046d:c52b class-ID: 0300
Device-3: 1-10:5 info: Logitech Gaming Mouse G300 type: Mouse,Keyboard
driver: hid-generic,usbhid interfaces: 2 rev: 2.0 speed: 12 Mb/s
power: 200mA chip-ID: 046d:c246 class-ID: 0300
Device-4: 1-11:6 info: Razer USA Razer Chroma Addressable RGB Controller
type: HID driver: hid-generic,usbhid interfaces: 3 rev: 2.0 speed: 12 Mb/s
power: 500mA chip-ID: 1532:0f1f class-ID: 0300
Device-5: 1-12:7 info: Apple Bluetooth Host Controller
type: Keyboard,Mouse,Bluetooth driver: btusb,hid-generic,usbhid
interfaces: 6 rev: 2.0 speed: 12 Mb/s chip-ID: 05ac:8290 class-ID: fe01
Hub-3: 2-0:1 info: Full speed (or root) Hub ports: 10 rev: 3.1
speed: 10 Gb/s chip-ID: 1d6b:0003 class-ID: 0900
Hub-4: 2-1:2 info: VIA Labs VL812 Hub ports: 4 rev: 3.0 speed: 5 Gb/s
chip-ID: 2109:0812 class-ID: 0900
Sensors:
System Temperatures: cpu: 59.0 C mobo: 27.8 C gpu: amdgpu temp: 46.0 C
mem: 46.0 C
Fan Speeds (RPM): N/A gpu: amdgpu fan: 0
Info:
Processes: 252 Uptime: 1m wakeups: 0 Init: systemd v: 249 tool: systemctl
Compilers: gcc: 11.1.0 clang: 12.0.1 Packages: 1609 pacman: 1600 lib: 450
flatpak: 9 Shell: Zsh (sudo) v: 5.8 running-in: tty pts/0 (SSH) inxi: 3.3.06 ```
Welcome to Manjaro! 
to give us more information so we can see what’s really going on.
this message and I’ll come back and have another look.