I have been using Manjaro on my Thinkpad T420 since two years ago with no hardware problems. Most of the time I have the laptop connected to an external Samsung monitor via DisplayPort-to-HDMI adaptor and, recently, via VGA. The reason I switched from DP/HDMI to VGA was because the monitor stopped working after an update of the OS when connected via DP/HDMI. Since it was working via the VGA port, I just kept working and ignored the issue… Until yesterday, when I did another update of Manjaro and the external screen, although is detected by the system, is not working anymore.
My first thought was that there was a hardware problem. I tried the screen with another laptop, and it works with both the HDMI and VGA ports; as for the laptop, I am not sure, because I don’t have another external monitor to test it with.
Searching here in the Forum, I found a post suggesting to try older kernels, since this is old hardware (my laptop is from 2011). I rebooted the computer using kernels 4.14, 4.19, and 5.4, all of which I have happily used before, but without avail: the external monitor is detected (but is not working) when I use the VGA port, and is not detected at all if the DP/HDMI port is used instead (I reconnected the cables several times).
This might be a hardware failure, but any hint on how to be sure of the cause of the problem and find a solution?
Here are some outputs that might be helpful.
❯ inxi -Fazy
System:
Kernel: 4.19.180-1-MANJARO x86_64 bits: 64 compiler: gcc v: 10.2.0
parameters: BOOT_IMAGE=/boot/vmlinuz-4.19-x86_64
root=UUID=7237cc4d-9ab7-410c-90c4-b8c90e2b10df rw quiet apparmor=1
security=apparmor udev.log_priority=3
Desktop: KDE Plasma 5.21.3 tk: Qt 5.15.2 info: latte-dock wm: kwin_x11 vt: 1
dm: SDDM Distro: Manjaro Linux base: Arch Linux
Machine:
Type: Laptop System: LENOVO product: 4180Q3U v: ThinkPad T420
serial: <filter> Chassis: type: 10 serial: <filter>
Mobo: LENOVO model: 4180Q3U serial: <filter> UEFI-[Legacy]: LENOVO
v: 83ET82WW (1.52 ) date: 06/04/2018
Battery:
ID-1: BAT0 charge: 37.7 Wh (100.0%) condition: 37.7/56.2 Wh (67.1%)
volts: 12.4 min: 10.8 model: SANYO 45N1001 type: Li-ion serial: <filter>
status: Full
CPU:
Info: Dual Core model: Intel Core i7-2640M bits: 64 type: MT MCP
arch: Sandy Bridge family: 6 model-id: 2A (42) stepping: 7 microcode: 2F
cache: L2: 4 MiB
flags: avx lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 22326
Speed: 797 MHz min/max: 800/3500 MHz Core speeds (MHz): 1: 797 2: 797 3: 797
4: 797
Vulnerabilities: Type: itlb_multihit status: KVM: Vulnerable
Type: l1tf mitigation: PTE Inversion
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 status: Not affected
Type: tsx_async_abort status: Not affected
Graphics:
Device-1: Intel 2nd Generation Core Processor Family Integrated Graphics
vendor: Lenovo ThinkPad T420 driver: i915 v: kernel bus-ID: 00:02.0
chip-ID: 8086:0126 class-ID: 0300
Device-2: Chicony integrated camera type: USB driver: uvcvideo
bus-ID: 1-1.6:5 chip-ID: 04f2:b221 class-ID: 0e02
Display: x11 server: X.Org 1.20.10 compositor: kwin_x11 driver:
loaded: intel unloaded: modesetting alternate: fbdev,vesa display-ID: :0
screens: 1
Screen-1: 0 s-res: 1920x1980 s-dpi: 96 s-size: 507x523mm (20.0x20.6")
s-diag: 728mm (28.7")
Monitor-1: LVDS1 res: 1600x900 hz: 60 dpi: 131 size: 310x170mm (12.2x6.7")
diag: 354mm (13.9")
Monitor-2: VGA1 res: 1920x1080 hz: 60 dpi: 96 size: 510x290mm (20.1x11.4")
diag: 587mm (23.1")
OpenGL: renderer: Mesa DRI Intel HD Graphics 3000 (SNB GT2)
v: 3.3 Mesa 20.3.4 compat-v: 3.0 direct render: Yes
Audio:
Device-1: Intel 6 Series/C200 Series Family High Definition Audio
vendor: Lenovo driver: snd_hda_intel v: kernel bus-ID: 00:1b.0
chip-ID: 8086:1c20 class-ID: 0403
Sound Server-1: ALSA v: k4.19.180-1-MANJARO running: yes
Sound Server-2: JACK v: 0.125.0 running: no
Sound Server-3: PulseAudio v: 14.2 running: yes
Sound Server-4: PipeWire v: 0.3.23 running: no
Network:
Device-1: Intel 82579LM Gigabit Network vendor: Lenovo ThinkPad T520
driver: e1000e v: 3.2.6-k port: 5080 bus-ID: 00:19.0 chip-ID: 8086:1502
class-ID: 0200
IF: enp0s25 state: up speed: 1000 Mbps duplex: full mac: <filter>
Device-2: Intel Centrino Advanced-N 6205 [Taylor Peak] driver: iwlwifi
v: kernel port: efa0 bus-ID: 03:00.0 chip-ID: 8086:0085 class-ID: 0280
IF: wlp3s0 state: up mac: <filter>
IF-ID-1: wwp0s29u1u4i6 state: down mac: <filter>
Bluetooth:
Device-1: Broadcom BCM2045B (BDC-2.1) type: USB driver: btusb v: 0.8
bus-ID: 1-1.4:4 chip-ID: 0a5c:217f class-ID: fe01 serial: <filter>
Report: This feature requires one of these tools: hciconfig/bt-adapter
Drives:
Local Storage: total: 1.36 TiB used: 952.87 GiB (68.2%)
SMART Message: Unable to run smartctl. Root privileges required.
ID-1: /dev/sda maj-min: 8:0 vendor: Samsung model: SSD 860 EVO 500GB
size: 465.76 GiB block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s
rotation: SSD serial: <filter> rev: 3B6Q scheme: MBR
ID-2: /dev/sdb maj-min: 8:16 vendor: HGST (Hitachi) model: HTS541010A9E680
size: 931.51 GiB block-size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s
rotation: 5400 rpm serial: <filter> rev: A7G0 scheme: MBR
Partition:
ID-1: / raw-size: 65.37 GiB size: 63.84 GiB (97.67%) used: 47.02 GiB (73.7%)
fs: ext4 dev: /dev/sda1 maj-min: 8:1
ID-2: /home raw-size: 400.39 GiB size: 393.11 GiB (98.18%)
used: 216.01 GiB (54.9%) fs: ext4 dev: /dev/sda2 maj-min: 8:2
Swap:
Alert: No Swap data was found.
Sensors:
System Temperatures: cpu: 49.0 C mobo: N/A
Fan Speeds (RPM): cpu: 3167
Info:
Processes: 205 Uptime: 19m wakeups: 1 Memory: 15.55 GiB
used: 3.06 GiB (19.7%) Init: systemd v: 247 tool: systemctl Compilers:
gcc: 10.2.0 clang: 11.1.0 Packages: 2061 pacman: 2054 lib: 461 flatpak: 0
snap: 7 Shell: Zsh v: 5.8 running-in: konsole inxi: 3.3.03
❯ xrandr --listproviders
Providers: number : 1
Provider 0: id: 0x4b cap: 0xb, Source Output, Sink Output, Sink Offload crtcs: 3 o
utputs: 9 associated providers: 0 name:Intel
❯ xrandr
Screen 0: minimum 8 x 8, current 1920 x 1980, maximum 32767 x 32767
LVDS1 connected primary 1600x900+170+1080 (normal left inverted right x axis y axis) 310mm x 170mm
1600x900 60.00*+
1400x900 59.88
1368x768 60.00 59.88 59.85
1280x800 59.81 59.91
1280x720 59.86 60.00 59.74
1024x768 60.00
1024x576 60.00 59.90 59.82
960x540 60.00 59.63 59.82
800x600 60.32 56.25
864x486 60.00 59.92 59.57
800x450 60.00
640x480 59.94
720x405 59.51 60.00 58.99
640x360 59.84 59.32 60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP3 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)
VGA1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 510mm x 290mm
1920x1080 60.00*+
1600x1200 60.00
1680x1050 59.95
1280x1024 60.02
1440x900 59.89
1280x960 60.00
1280x800 59.81
1024x768 60.00
800x600 60.32 56.25
640x480 59.94
VIRTUAL1 disconnected (normal left inverted right x axis y axis)