Installation problem - HDMI monitor is recognised but doesn't work.

[Andy3142]

I'm attempting to trial Kubuntu but having a real struggle to get my second, HDMI, monitor working. I'm also having the same issue in Mint and Antix.

System details are:
Operating System: Kubuntu 25.10
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.2
Kernel Version: 6.17.0-5-generic (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i5-7200U CPU @ 2.50GHz
Memory: 8 GiB of RAM (7.6 GiB usable)
Graphics Processor 1: Intel® HD Graphics 620
Graphics Processor 2: AMD Radeon R5 M445 Series
Manufacturer: Dell Inc.
Product Name: Inspiron 5567
The HDMI monitor is a Lenovo C22-10. Both it and the laptop screen are 1920 x 1080

After installing from USB (legacy boot, UEFI doesn't work) on the laptop screen everything is as normal. However the HDMI monitor shows a pretty spash screen but gets stuck there: no menus appear, no GUI or text prompt, the mouse doesn't show, it's dead. However, the laptop is nevertheless connected to the Lenovo. In Kubuntu the Identify Monitor flashes up the correct name on both screens. Antix has a text-based system monitor, and this (only) does show on the Lenovo. In Mint if I fiddle round with the resolutions then the GUI does appear on the Lenovo but it is completely distorted and I can't find any combination of resolutions that works on both laptop and Lenovo.

I wan't sure which other parts of the Kubuntu system information to download, though of course I can. Meanwhile here is what Antix reports in the hope it may be some use meanwhile.

Graphics:
Device-1: Intel HD Graphics 620 vendor: Dell driver: i915 v: kernel arch: Gen-9.5
process: Intel 14nm built: 2016-20 ports: active: HDMI-A-1,eDP-1 empty: none bus-ID: 00:02.0
chip-ID: 8086:5916 class-ID: 0300
Device-2: AMD Topaz XT [Radeon R7 M260/M265 / M340/M360 M440/M445 530/535 620/625 Mobile]
vendor: Dell driver: amdgpu v: kernel arch: GCN-3 code: Volcanic Islands process: TSMC 28nm
built: 2014-19 pcie: gen: 1 speed: 2.5 GT/s lanes: 4 link-max: gen: 3 speed: 8 GT/s lanes: 8
bus-ID: 01:00.0 chip-ID: 1002:6900 class-ID: 0380 temp: 56.0 C
Device-3: Logitech HD Pro Webcam C920 driver: snd-usb-audio,uvcvideo type: USB rev: 2.0
speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 1-2.4.4.4:10 chip-ID: 046d:082d class-ID: 0102
serial: <filter>
Device-4: Microdia Integrated_Webcam_HD driver: uvcvideo type: USB rev: 2.0 speed: 480 Mb/s
lanes: 1 mode: 2.0 bus-ID: 1-5:3 chip-ID: 0c45:6a06 class-ID: 0e02
Display: server: X.Org v: 1.21.1.7 driver: X: loaded: amdgpu,modesetting unloaded: fbdev,vesa
dri: iris gpu: i915 display-ID: :0.0 screens: 1
Screen-1: 0 s-res: 3840x1080 s-dpi: 96 s-size: 1016x285mm (40.00x11.22")
s-diag: 1055mm (41.54")
Monitor-1: not-matched mapped: HDMI-1 pos: right res: 1920x1080 hz: 60 dpi: 102
size: 476x268mm (18.74x10.55") diag: 546mm (21.51") modes: N/A
Monitor-2: not-matched mapped: eDP-1 pos: primary,left res: 1920x1080 hz: 60 dpi: 142
size: 344x193mm (13.54x7.6") diag: 394mm (15.53") modes: N/A
API: EGL v: 1.5 hw: drv: intel iris drv: amd radeonsi platforms: device: 0 drv: iris device: 1
drv: radeonsi device: 2 drv: swrast gbm: drv: iris surfaceless: drv: radeonsi x11: drv: iris
inactive: wayland
API: OpenGL v: 4.6 vendor: intel mesa v: 22.3.6 glx-v: 1.4 es-v: 3.2 direct-render: yes
renderer: Mesa Intel HD Graphics 620 (KBL GT2) device-ID: 8086:5916 memory: 7.4 GiB unified: yes

This is totally beyond me troubleshoot; what should I try please??

With many thanks

[oshunluvr]

So you've got two video cards so maybe it's a driver issue. I assume in System Settings you have both monitors enabled and correctly configured.

You might be able to turn off one of the two video cards in BIOS which might just let it work.

Normally, when booting, you should see both monitors displaying the same thing - the GRUB menu for example - all the way until you log in. If not, you might have a BIOS connection/configuration issue.

This:

Monitor-1: not-matched mapped: HDMI-1 pos: right res: 1920x1080 hz: 60 dpi: 102
size: 476x268mm (18.74x10.55") diag: 546mm (21.51") modes: N/A
Monitor-2: not-matched mapped: eDP-1 pos: primary,left res: 1920x1080 hz: 60 dpi: 142
size: 344x193mm (13.54x7.6") diag: 394mm (15.53") modes: N/A

says to me that both are detected and connected. Expanding your desktop to the second monitor should just work. Make sure both monitors have "Device" Enabled" checked in System Settings and that they are not "on top" of each other (drag the monitor boxes so they don't overlap).

Or you may simply not have both sets of video drivers installed.