Display output incompatible

I am running IPFire on a mini desktop.

When the PC boots with the monitor connected and on, it boots as normal, to the login prompt.

IPFire is running and working as expected. Can login, logout and get to it from the web interface else where on my LAN.

But, if I turn off the monitor and turn it back on, The display shows “incompatible input”. IPFire continues fine, but, I can’t login to the actual PC.

Any ideas? Is there a setting? There doesn’t seem to be any BIOS settings and the same happens on every monitor I’ve tried.

I found one reference to a similar problem with Mint, where it was solved by updating the kernel to 6.5.

But, System info in the web UI says IPFire is running 6.6.47-ipfire

Would you kindly share more details about this mini desktop?
The display? How you connected these two devices? VGA cable or what?

The PC is a GMKtec NUKbox G2. It has HDMI and Displayport outputs.

I have tried all of those ports connected to various monitors, an old Dell VGA (with appropriate adapter), Acer with HDMI (HDMI-HDMI, DP-HDMI, HDMI-VGA), and an HDMI WIMAXI (HDMI-HDMI).

All work with other PC’s (and I think they worked with the GMKtec, before wiping Windows, though I didn’t notice the issue then so probably didn’t test different monitors.)

Thanks for sharing. Short answer: interesting but ewww.

More details

Tech specs are really interesting

Intel 12th Alder Lake- N100, 4C/4T, 7nm, MAX3.4G, 6 MB Cache, TDP 6W
Intel UHD Graphics (Up to 750MHz) 24 execution units 12GB LPDDR5 4800
1TB shipped, M.2 2242 SATA, max 2TB
Window 11 Pro (installed), supports Linux
BT5.2 / WiFi 6/
3 displays–HDMI (4K@60Hz)2, DP (4K@60Hz)1
USB3.2(Gen1
1 5Gbps/S)3
HDMI
2 4096 x 2160@60Hz/ DP V1.4
1 4096 x 2160@60Hz/
1*3.5 mm headphone jack
Giga LAN (RJ45)*2 1000M/

for less than 150 euros, it’s really interesting
And the performance for power ratio, compared with a staggering 10 years old embedded CPU is really interesting
Intel N100 vs AMD GX-412TC SOC [cpubenchmark.net] by PassMark Software

But here comes the “issues”… at least for use this box as IpFire installation: the “update” of the bios or drivers is… a 10gb file stored on google drive, requiring a google account to download it. A computer brand should not provide updates in this way, should at least provide the opportunity to download more recent drivers/bios as singolar file (better an installer, but whatever) with at least some changelog.

Moreover: this product seems to me designed to be used as client computer, not kept connected (if lucky) to a kvm and running 24/7.
End of evaluation, getting to the point…

I’m currently not aware if the Alder Lake display interface is perfectly managed for IPFire, which mostly rely for graphics card drivers to Linux kernel (it’s really not interesting for a firewall distro, unless GPU could be used for cypher/cryptography… IDK if that’s posible), but there’s anyway a chance that part of the issues you’re encountering could be caused by a less than perfect implementation of the video output into the mainboard bios/firmware while connecting/disconnecting cables. AFAIK, a lot of mainboards that do not have HDMI connected at boot, do not consider anymore that port for output as primary display; dummy plugs are available for that.

Unfortunately, seems harder than usual understand if GMTek released updated bios/firmware for that board, with the changelog of the issue managed.

As far as I can see, your monitors should not be blamed for this erratic behaviour. I don’t know if this box will be close to other computers you’re using, probably a KVM could partially ease the problem? Not a fix, possibly… a hardware bandaid.

Problem is, I think there is something up with those Nx00 video drivers as my N200 MSI have flaky monitors regardless of OS. In windows, one monitor will intermittently stay black after screen blank or power down and its not always the same monitor port either. I also have Ubuntu on that system and it does the same thing. For me, unplugging and plugging back in the monitor fixes it, so I have to guess a driver issue talking to hardware. I am going to dig into the UEFI bios and see if disabling some power management options changes this behaviour.

Also this monitor issue happens every once in a while on cold boot.