Dual monitor with HDMI keeps connecting and disconnecting in Linux with Ultra 7 255H

Shaun2 · ‎10-24-2025

Hi, I'm using a laptop with Intel Ultra 7 255H. When I use Linux (Linux mint), once I connect an external monitor via HDMI cable, the monitor keeps switching and flickering. However, when I use only the external monitor (i.e., with the laptop lid closed), everything works normally. Therefore, the HDMI cable is not the issue. And when I use a dual monitor in Windows, everything is also fine. I have tried updating the kernel and installing Ubuntu. However, the issue persists.

Please note the refresh rate of my internal monitor is 120 Hz, whereas the external is 60 Hz. I don't know if this is the cause of the problem. I have also changed the refresh rate of the internal monitor to 60. However, once I plug in the HDMI cable, the refresh rate becomes 120 Hz.

Sorry about my English. I also upload a video. https://drive.google.com/file/d/1hKYB9S ... sp=sharing

Here is my system and hardware information

System:
  Kernel: 6.14.0-33-generic arch: x86_64 bits: 64 compiler: gcc v: 13.3.0 clocksource: tsc
  Desktop: Cinnamon v: 6.4.8 tk: GTK v: 3.24.41 wm: Muffin v: 6.4.1 vt: 7 dm: LightDM v: 1.30.0
    Distro: Linux Mint 22.2 Zara base: Ubuntu 24.04 noble
Machine:
  Type: Laptop System: MECHREVO product: CODE Series v: Standard serial: <superuser required>
  Mobo: MECHREVO model: CODE Series-X5AR4NAG v: Standard serial: <superuser required>
    part-nu: 0001 uuid: <superuser required> UEFI: American Megatrends LLC. v: N.1.13MRO01
    date: 05/30/2025
Battery:
  ID-1: BAT0 charge: 99.2 Wh (100.0%) condition: 99.2/99.2 Wh (100.0%) volts: 17.5 min: 15.5
    model: standard type: Li-ion serial: <filter> status: full
CPU:
  Info: 16-core model: Intel Core Ultra 7 255H bits: 64 type: MCP smt: <unsupported>
    arch: Arrow Lake rev: 2 cache: L1: 1.6 MiB L2: 28 MiB L3: 24 MiB
  Speed (MHz): avg: 1624 high: 4428 min/max: 400/5100:4400:2500 cores: 1: 1601 2: 1251 3: 400
    4: 1800 5: 1400 6: 1762 7: 879 8: 980 9: 1001 10: 4391 11: 400 12: 3802 13: 400 14: 4428 15: 1100
    16: 400 bogomips: 117964
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
  Device-1: Intel Arrow Lake-P [Intel Graphics] vendor: Tongfang Hongkong driver: i915 v: kernel
    arch: Gen-15 ports: active: HDMI-A-1 off: eDP-1 empty: DP-1, DP-2, DP-3, DP-4 bus-ID: 00:02.0
    chip-ID: 8086:7d51 class-ID: 0300
  Device-2: SunplusIT HD Webcam driver: uvcvideo type: USB rev: 2.0 speed: 480 Mb/s lanes: 1
    bus-ID: 3-3:2 chip-ID: 2b7e:b663 class-ID: 0e02 serial: <filter>
  Display: x11 server: X.Org v: 21.1.11 with: Xwayland v: 24.1.6 driver: X: loaded: modesetting
    unloaded: fbdev,vesa dri: iris gpu: i915 display-ID: :0 screens: 1
  Screen-1: 0 s-res: 1920x1080 s-dpi: 96 s-size: 508x286mm (20.00x11.26") s-diag: 583mm (22.95")
  Monitor-1: HDMI-A-1 mapped: HDMI-1 pos: primary model: AOC 27B1 serial: <filter> res: 1920x1080
    hz: 60 dpi: 82 size: 598x336mm (23.54x13.23") diag: 686mm (27") modes: max: 1920x1080
    min: 720x400
  Monitor-2: eDP-1 note: disabled model: BOE Display NE153QDM-NY1 res: 1920x1080 dpi: 198
    size: 329x206mm (12.95x8.11") diag: 388mm (15.3") modes: 2560x1600
  API: EGL v: 1.5 hw: drv: intel iris platforms: device: 0 drv: iris device: 1 drv: swrast gbm:
    drv: iris surfaceless: drv: iris x11: drv: iris inactive: wayland
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: intel mesa v: PPA glx-v: 1.4 direct-render: yes
    renderer: Mesa Intel Graphics (ARL) device-ID: 8086:7d51
Audio:
  Device-1: Intel vendor: Tongfang Hongkong driver: snd_hda_intel v: kernel bus-ID: 00:1f.3
    chip-ID: 8086:7728 class-ID: 0403
  API: ALSA v: k6.14.0-33-generic status: kernel-api
  Server-1: PipeWire v: 1.0.5 status: active with: 1: pipewire-pulse status: active
    2: wireplumber status: active 3: pipewire-alsa type: plugin
Network:
  Device-1: Intel driver: iwlwifi v: kernel port: N/A bus-ID: 00:14.3 chip-ID: 8086:7740
    class-ID: 0280
  IF: wlp0s20f3 state: up mac: <filter>
  Device-2: Motorcomm Micro. YT6801 Gigabit Ethernet vendor: Tongfang Hongkong driver: N/A pcie:
    speed: 2.5 GT/s lanes: 1 port: 4000 bus-ID: 2c:00.0 chip-ID: 1f0a:6801 class-ID: 0200
Bluetooth:
  Device-1: Intel AX201 Bluetooth driver: btusb v: 0.8 type: USB rev: 2.0 speed: 12 Mb/s lanes: 1
    bus-ID: 3-10:7 chip-ID: 8087:0026 class-ID: e001
  Report: hciconfig ID: hci0 rfk-id: 0 state: up address: <filter> bt-v: 5.2 lmp-v: 11
    sub-v: 4395 hci-v: 11 rev: 4395 class-ID: 7c010c
Drives:
  Local Storage: total: 953.87 GiB used: 33.53 GiB (3.5%)
  ID-1: /dev/nvme0n1 model: YMTC PC41Q-1TB-B size: 953.87 GiB speed: 63.2 Gb/s lanes: 4 tech: SSD
    serial: <filter> fw-rev: YM11D332 temp: 27.9 C scheme: GPT
Partition:
  ID-1: / size: 641.54 GiB used: 33.48 GiB (5.2%) fs: ext4 dev: /dev/nvme0n1p5
  ID-2: /boot/efi size: 96 MiB used: 55.3 MiB (57.6%) fs: vfat dev: /dev/nvme0n1p1
Swap:
  ID-1: swap-1 type: file size: 2 GiB used: 0 KiB (0.0%) priority: -2 file: /swapfile
USB:
  Hub-1: 1-0:1 info: hi-speed hub with single TT ports: 1 rev: 2.0 speed: 480 Mb/s lanes: 1
    chip-ID: 1d6b:0002 class-ID: 0900
  Hub-2: 2-0:1 info: super-speed hub ports: 4 rev: 3.1 speed: 20 Gb/s lanes: 2 chip-ID: 1d6b:0003
    class-ID: 0900
  Hub-3: 3-0:1 info: hi-speed hub with single TT ports: 12 rev: 2.0 speed: 480 Mb/s lanes: 1
    chip-ID: 1d6b:0002 class-ID: 0900
  Device-1: 3-3:2 info: SunplusIT HD Webcam type: video driver: uvcvideo interfaces: 4 rev: 2.0
    speed: 480 Mb/s lanes: 1 power: 500mA chip-ID: 2b7e:b663 class-ID: 0e02 serial: <filter>
  Hub-4: 3-5:3 info: Genesys Logic Hub ports: 2 rev: 2.1 speed: 480 Mb/s lanes: 1
    chip-ID: 05e3:0610 class-ID: 0900
  Hub-5: 3-6:4 info: Manufacturer hub ports: 4 rev: 2.0 speed: 12 Mb/s lanes: 1 power: 100mA
    chip-ID: 0a05:7211 class-ID: 0900
  Device-1: 3-6.2:5 info: Logitech G102 LIGHTSYNC Gaming Mouse type: mouse,HID
    driver: hid-generic,usbhid interfaces: 2 rev: 2.0 speed: 12 Mb/s lanes: 1 power: 300mA
    chip-ID: 046d:c09d class-ID: 0300 serial: <filter>
  Device-2: 3-6.3:6 info: CHERRY G83 (RS 6000) Keyboard type: keyboard driver: hid-generic,usbhid
    interfaces: 1 rev: 2.0 speed: 1.5 Mb/s lanes: 1 power: 100mA chip-ID: 046a:0011 class-ID: 0301
  Device-3: 3-10:7 info: Intel AX201 Bluetooth type: bluetooth driver: btusb interfaces: 2
    rev: 2.0 speed: 12 Mb/s lanes: 1 power: 100mA chip-ID: 8087:0026 class-ID: e001
  Hub-6: 4-0:1 info: super-speed hub ports: 2 rev: 3.1 speed: 20 Gb/s lanes: 2 chip-ID: 1d6b:0003
    class-ID: 0900
  Hub-7: 4-2:2 info: Genesys Logic GL3523 Hub ports: 2 rev: 3.2 speed: 5 Gb/s lanes: 1
    chip-ID: 05e3:0620 class-ID: 0900
Sensors:
  System Temperatures: cpu: 39.2 C mobo: N/A
  Fan Speeds (rpm): N/A
Repos:
  Packages: pm: dpkg pkgs: 2152
  No active apt repos in: /etc/apt/sources.list
  Active apt repos in: /etc/apt/sources.list.d/cappelikan-ppa-noble.list
    1: deb [signed-by=/etc/apt/keyrings/cappelikan-ppa-noble.gpg] https: //ppa.launchpadcontent.net/cappelikan/ppa/ubuntu noble main
  Active apt repos in: /etc/apt/sources.list.d/google-chrome.list
    1: deb [arch=amd64] https: //dl.google.com/linux/chrome/deb/ stable main
  Active apt repos in: /etc/apt/sources.list.d/kisak-kisak-mesa-noble.list
    1: deb [signed-by=/etc/apt/keyrings/kisak-kisak-mesa-noble.gpg] https: //ppa.launchpadcontent.net/kisak/kisak-mesa/ubuntu noble main
  Active apt repos in: /etc/apt/sources.list.d/kobuk-team-intel-graphics-noble.list
    1: deb [signed-by=/etc/apt/keyrings/kobuk-team-intel-graphics-noble.gpg] https: //ppa.launchpadcontent.net/kobuk-team/intel-graphics/ubuntu noble main
  Active apt repos in: /etc/apt/sources.list.d/official-package-repositories.list
    1: deb https: //mirrors.aliyun.com/linuxmint-packages zara main upstream import backport
    2: deb http: //mirrors.aliyun.com/ubuntu noble main restricted universe multiverse
    3: deb http: //mirrors.aliyun.com/ubuntu noble-updates main restricted universe multiverse
    4: deb http: //mirrors.aliyun.com/ubuntu noble-backports main restricted universe multiverse
    5: deb http: //security.ubuntu.com/ubuntu/ noble-security main restricted universe multiverse
Info:
  Memory: total: 32 GiB note: est. available: 30.88 GiB used: 4.2 GiB (13.6%)
  Processes: 379 Power: uptime: 33m states: freeze,mem,disk suspend: s2idle wakeups: 0
    hibernate: platform Init: systemd v: 255 target: graphical (5) default: graphical
  Compilers: gcc: 13.3.0 Client: Cinnamon v: 6.4.8 inxi: 3.3.34

KennethB_Intel · ‎10-26-2025

Hello Shaun2,

Thank you for reaching out to the Intel Community Forum. I understand that you are experiencing flickering and disconnection issues with your external monitor when using Linux Mint and an Intel Ultra 7 255H processor. I would like to ask a few questions to better understand the situation and assist you further:

How often does the flickering and disconnection happen? Is it random, or does it follow a pattern?
Aside from the steps you already tried, have you attempted any other troubleshooting methods?
Could you confirm the exact model of your monitor and the HDMI cable version you are using?
Could you please provide us the SSU logs of your system? Please download Intel® System Support Utility for the Linux* Operating System and scan your system so I can further check this.

Please reply with the details at your earliest convenience so I can continue to assist you.

Thank you.

Best regards,

Kenneth B.

Intel Customer Support Technician