topic Re: Re:Dual monitor with HDMI keeps connecting and disconnecting in Linux with Ultra 7 255H in Graphics

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

Shaun2 — Fri, 24 Oct 2025 09:45:17 GMT

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

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

KennethB_Intel — Mon, 27 Oct 2025 04:06:10 GMT

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

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

KennethB_Intel — Thu, 30 Oct 2025 04:56:30 GMT

Hello Shaun2,

Just checking in to see if you had a chance to review and respond to the questions I shared earlier. Your input will help me proceed with the next steps to support you further.

Best regards,

Kenneth B.

Intel Customer Support Technician

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

Shaun2 — Sat, 01 Nov 2025 02:29:03 GMT

Hi Kenneth,

Thanks for your reply.

How often does the flickering and disconnection happen? Is it random, or does it follow a pattern?

As you can see in the video, once I plug in the HDMI cable, the screen keeps flickering and connecting and disconnecting. It is not random.

Aside from the steps you already tried, have you attempted any other troubleshooting methods?

I have tried to install other Linux systems (including Ubuntu and Arch Linux) and update to the latest kernel. I have also tried to set the refresh rate of both the internal and external monitors to 60 Hz. However, none of these methods were effecitive.

Could you confirm the exact model of your monitor and the HDMI cable version you are using?

My monitor is AOC 27B1H. I don't think the monitor nor the HDMI cable is the issue. Because I have changed the monitor and the cable.

Could you please provide us the SSU logs of your system?

Please see the attachment.

Thanks for your help.

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

KennethB_Intel — Mon, 03 Nov 2025 04:01:40 GMT

Hello Shaun2,

Thank you for the update and for confirming that you have already tested with a different monitor and HDMI cable.

I understand you believe the cable or monitor may not be the issue. However, could you please confirm the specific HDMI cables you have tried so I can further review this? If you have tested other cables, kindly let me know their versions as well.

Additionally, have you already updated the graphics driver through your laptop manufacturer's official website? This helps ensure the driver is properly optimized for your system's hardware.

I will wait for your response so I can continue assisting you.

Best regards,

Kenneth B.

Intel Customer Support Technician

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

KennethB_Intel — Thu, 06 Nov 2025 05:43:15 GMT

Hello Shaun2,

Just checking in to see if you had a chance to review and respond to the questions I shared earlier. Your input will help me proceed with the next steps to support you further.

Best regards,

Kenneth B.

Intel Customer Support Technician

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

Shaun2 — Thu, 06 Nov 2025 15:26:49 GMT

Hi Kenneth,

My apologies for the delayed response.

I have tested on the HDMI 1.4 and 2.1 tables. Here is the order link

Functionality is nominal when operating on Windows11. Converserly, upon migrating to a Linux environment, including distributions such as Ubuntu and Linux Mint, the aforementioned display malfunction is observed.

I also asked this question on the Linux Mint Forums and uploaded some videos. You can kindly refer to this link

Once again, thanks for your help

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

KennethB_Intel — Thu, 06 Nov 2025 22:21:28 GMT

Hello Shaun2,

Thank you for your response. Please allow me to further check this internally. I'll provide you an update once I have more information.

Thanks!

Best regards,

Kenneth B.

Intel Customer Support Technician

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

RandyT_Intel — Mon, 10 Nov 2025 02:13:43 GMT

Hello Shaun2,

I'm reaching out on behalf of Kenneth regarding your recent inquiry.

Before we proceed with any testing or troubleshooting, I wanted to check a few important items with you to ensure we're working with the optimal setup:

Could you please confirm whether you have tested with the latest driver and kernel versions? This will help ensure you have access to the most up-to-date optimizations and support features. For reference, the latest stable release of Mesa is 25.2.6.

I also want to set the proper expectation that Ubuntu is the only officially supported Linux distribution for our solutions. If you're using a different distribution, this may impact our ability to provide full support.

For detailed information about driver requirements and installation, please refer to our documentation: https://dgpu-docs.intel.com/driver/client/overview.html

Additionally, if you have access to a Windows operating system, could you please test if the issue persists when running Windows in Safe Mode? If the flickering ceases in Safe Mode, this could indicate a potential OS-related problem or driver conflict, which would help us narrow down the root cause. For further isolation purposes, could you also check if the flickering is present in the BIOS environment? This will help us determine if the issue is hardware-related or software/driver-related.

Please let me know the status of your current driver/kernel versions and your Linux distribution so we can proceed accordingly.

Thank you for your time, and I look forward to your response.

Best regards,

Randy T.

Intel Customer Support Technician

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

Shaun2 — Mon, 10 Nov 2025 15:40:14 GMT

Dear Randy,

Thanks for your reply.

> Could you please confirm whether you have tested with the latest driver and kernel versions?

I have tested with the latest driver, including the HWE driver. However, using these latest kernels has not resolved my issue. On the contrary, some kernels even cause the wireless adapter to malfunction.

> For reference, the latest stable release of Mesa is 25.2.6.

I have not tried the latest Mesa. I'll give it a try.

> I also want to set the proper expectation that Ubuntu is the only officially supported Linux distribution for our solutions. If you're using a different distribution, this may impact our ability to provide full support.

I have tried with Ubuntu 24.04.3. But this issue still persists, and it is consistent with the same problem in Linux Mint. If using Ubuntu would help you resolve the issue more effectively, I would be glad to do so.

>Additionally, if you have access to a Windows operating system, could you please test if the issue persists when running Windows in Safe Mode? If the flickering ceases in Safe Mode, this could indicate a potential OS-related problem or driver conflict, which would help us narrow down the root cause. For further isolation purposes, could you also check if the flickering is present in the BIOS environment? This will help us determine if the issue is hardware-related or software/driver-related.

I plan to try again soon and will post an update as soon as I have a result. Please note that I disabled Secure Boot because it's a dual boot setup with Windows and Linux Mint. However, I don't believe that's the cause, as disabling Secure Boot should only resolve issues, not create new ones.

Thanks again. I'll post an update as soon as there's any progress.

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

RandyT_Intel — Mon, 10 Nov 2025 20:33:05 GMT

Hello Shaun2,

I appreciate your effort in trying my recommendations. Please inform us of any findings and observations after you've completed those steps. Thank you for your cooperation.

Best regards,

Randy T.

Intel Customer Support Technician

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

KennethB_Intel — Thu, 13 Nov 2025 04:21:24 GMT

Hello Shaun2,

I wanted to kindly check if you have had the chance to test with the latest Mesa version and perform the Windows Safe Mode and BIOS checks as planned.

Your feedback will help us narrow down the root cause and proceed with the next steps. Please let me know the results at your earliest convenience.

Best regards,

Kenneth B.

Intel Customer Support Technician

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

Shaun2 — Sat, 15 Nov 2025 07:36:04 GMT

Hi Kenneth,

I appreciate your persistent follow-up on this matter.

> Could you please confirm whether you have tested with the latest driver and kernel versions? This will help ensure you have access to the most up-to-date optimizations and support features. For reference, the latest stable release of Mesa is 25.2.6.

I have installed the latest version of Mesa.

client glx vendor string: Mesa Project and SGI Device: Mesa Intel(R) Graphics (ARL) (0x7d51) OpenGL renderer string: Mesa Intel(R) Graphics (ARL) OpenGL core profile version string: 4.6 (Core Profile) Mesa 25.2.7 - kisak-mesa PPA OpenGL version string: 4.6 (Compatibility Profile) Mesa 25.2.7 - kisak-mesa PPA OpenGL ES profile version string: OpenGL ES 3.2 Mesa 25.2.7 - kisak-mesa PPA

Also, I have updated the kernel to the latest version. But the issue still persists.

gao@gao-CODE-Series:~/Desktop$ uname -a Linux gao-CODE-Series 6.14.0-35-generic #35~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Oct 14 13:55:17 UTC 2 x86_64 x86_64 x86_64 GNU/Linux gao@gao-CODE-Series:~/Desktop$ cat /etc/os-release NAME="Linux Mint" VERSION="22.2 (Zara)" ID=linuxmint ID_LIKE="ubuntu debian" PRETTY_NAME="Linux Mint 22.2" VERSION_ID="22.2" HOME_URL="https://www.linuxmint.com/" SUPPORT_URL="https://forums.linuxmint.com/" BUG_REPORT_URL="http://linuxmint-troubleshooting-guide.readthedocs.io/en/latest/" PRIVACY_POLICY_URL="https://www.linuxmint.com/" VERSION_CODENAME=zara UBUNTU_CODENAME=noble

> Additionally, if you have access to a Windows operating system, could you please test if the issue persists when running Windows in Safe Mode? If the flickering ceases in Safe Mode, this could indicate a potential OS-related problem or driver conflict, which would help us narrow down the root cause. For further isolation purposes, could you also check if the flickering is present in the BIOS environment? This will help us determine if the issue is hardware-related or software/driver-related.

When I start Windows in Safe Mode, the external monitor is not detected. In the BIOS environment, the monitor also cannot be detected. Please see the image below.

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

KennethB_Intel — Tue, 18 Nov 2025 05:56:37 GMT

Hello Shaun2,

Since I have not heard back from you, I will now close this inquiry. If you need any further assistance, please submit a new question. Kindly note that this thread will no longer be monitored.

Best regards,

Kenneth B.

Intel Customer Support Technician