Samsung monitor display stays black

[EricvR]

Hello,
I have installed Rocky Linux 9.5 on my HP Elitebook. The notebook has 3 display ports (1 on notebook, 2 on docking station). I have a Fujitsu P23T-6 IPS monitor connected to the display ports and this works. However connecting my Samsung LC32G7xT monitor to these ports, the screen stays black.

ddcutil detect --stats errors -v

Display 1
I2C bus: /dev/i2c-10
DRM connector: card0-DP-3
Driver: radeon
I2C address 0x50 (EDID) responsive: true
Is eDP device: false
Is LVDS device: false
/sys/bus/i2c/devices/i2c-10/name card0-DP-3
PCI device path: /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/card0/card0-D
P-3/i2c-10
EDID synopsis:
Mfg id: SAM - Samsung Electric Company
Model: LC32G7xT
Product code: 28760 (0x7058)
Serial number: H4ZTA00343
Binary serial number: 1129859671 (0x43584a57)
Manufacture year: 2022, Week: 44
EDID version: 1.4
Extra descriptor:
Video input definition: 0xb5 - Digital Input (DisplayPort), Bit depth: 10
Supported features:
DPMS active-off
Digital display type: RGB 4:4:4 + YCrCb 4:4:4 + YCrCb 4:2:2
Standard sRGB color space: True
White x,y: 0.313, 0.329
Red x,y: 0.692, 0.297
Green x,y: 0.277, 0.651
Blue x,y: 0.146, 0.064
Extension blocks: 2
EDID source: I2C
EDID hex dump:
+0 +4 +8 +c 0 4 8 c
+0000 00 ff ff ff ff ff ff 00 4c 2d 58 70 57 4a 58 43 …L-XpWJXC
+0010 2c 20 01 04 b5 46 28 78 3b 43 a5 b1 4c 47 a6 25 , …F(x;C…LG.%
+0020 10 50 54 bf ef 80 81 c0 81 00 81 80 95 00 a9 c0 .PT…
+0030 b3 00 71 4f 01 01 98 e2 00 a0 a0 a0 29 50 08 3d …qO…)P.=
+0040 35 00 ba 89 21 00 00 1a 00 00 00 fd 0c 3c f0 67 5…!..<.g
+0050 67 62 01 0a 20 20 20 20 20 20 00 00 00 fc 00 4c gb… …L
+0060 43 33 32 47 37 78 54 0a 20 20 20 20 00 00 00 ff C32G7xT. …
+0070 00 48 34 5a 54 41 30 30 33 34 33 0a 20 20 02 e4 .H4ZTA00343. …
VCP version: Detection failed
Controller mfg: DDC communication failed
Firmware version: DDC communication failed
Monitor returns DDC Null Response for unsupported features: true

As ddcutil shows, there is communication to this monitor.

Any suggestions how to let this monitor work is highly appreciated.
Eric

[jbkt23]

Try a different cable. On my Lenovo t14 I had to use a display port on the monitor to a usb C port cable on the laptop to get my external monitor to work. But it could be you just need a better quality cable.

[EricvR]

Thanks for the reply.
I tried 2 different cables, both on notebook and docking station. But it doesn’t work (screen stays black).