Xorg detects no displays with an Intel UHD 630

**Setup** I'm trying to build a new media PC, and chose a low-power Intel Core i5 10600T processor, which has an integrated UHD 630 graphics chip. The motherboard is an ASUS Prime B560M-A and the display used is a Sony Bravia KDL-55W905A. I am using Debian testing (Bullseye), XFCE and lightdm. **Problem details** It seems that no displays are detected by the graphics chip at all. I get graphics at boot time and in BIOS, but when the system tries to start X, the screen goes blank permanently. Nothing is displayed in the X terminal and regular terminals cannot be accessed with for ex. Ctrl-Alt-F[something]. However, as expected, the computer responds normally to SSH access and I can interact with it remotely. The Xorg log file is here: https://pastebin.com/XCpjxe3y The offending line seems to be this: [ 3.859] (WW) modeset(0): No outputs definitely connected, trying again... lspci -v gives this output which seems fine: 00:02.0 VGA compatible controller: Intel Corporation CometLake-S GT2 [UHD Graphics 630] (rev 03) (prog-if 00 [VGA controller]) DeviceName: Onboard - Video Subsystem: ASUSTeK Computer Inc. UHD Graphics 630 Flags: bus master, fast devsel, latency 0, IRQ 140, IOMMU group 1 Memory at 6000000000 (64-bit, non-prefetchable) [size=16M] Memory at 4000000000 (64-bit, prefetchable) [size=256M] I/O ports at 3000 [size=64] Expansion ROM at 000c0000 [virtual] [disabled] [size=128K] Capabilities: Vendor Specific Information: Len=0c Capabilities: Express Root Complex Integrated Endpoint, MSI 00 Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [d0] Power Management version 2 Capabilities: Process Address Space ID (PASID) Capabilities: Address Translation Service (ATS) Capabilities: Page Request Interface (PRI) Kernel driver in use: i915 Kernel modules: i915 dmesg log shows problems with the video card at 1.046225, 1.061414, 1.063566 and 1.063917: https://pastebin.com/M1DCCDZ4 **What have I tried** For the record, I have an older and slower media PC machine with Core i5 4590T and its integrated graphics chip. This system works perfectly fine with the same TV. - The motherboard has two HDMI outputs and one DP output. None of these work. - Different cables have been tried, including cables which work with the same TV and the older media PC machine. - When booting from an Ubuntu liveCD, The exact same thing happens. - I cannot access xrandr to check on displays, because X does not start. - Setting i915.modeset=0 in grub config gets me to X at 1024x768 (only). In this state, xrandr runs, but does does not seem to give any sensible output and the resolution cannot be changed from X settings. - Finally, the xserver-xorg-video-intel package description states that it should not be used for systems newer than 2007. I have uninstalled the package, but this did not seem to have any effect. The Xorg log after this has been done is here: https://pastebin.com/MwqvwmWL I'm at my wit's end. Of course I could order a low-end graphics card and add it to the system, but would prefer not to. Any help is appreciated. **Additional questions** As said, if I set i915.modeset=0, I get to X, but the graphics are severely limited. I am also unsure about what the option truly does internally. Can I work with this state in some way to force a better resolution? Does HW acceleration work in this state?