Raspberry Pi 4 Tutorial - fatal error

Thanks for the tutorial. I followed the tutorial in headless mode (ssh); ran into a problem. After building the preempt rt kernel, DEPMOD reported a different version (I didn't write it down). After installation and subsequent edit of the /boot/cmdline.txt to append the text, I did reboot, but the device is no longer accessible to the network - not via wifi and not via ethernet. Suggestions?
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on edit:
Obtained a micro hdmi adapter so as to view the boot process, the device shuts down on a kernel panic.

I'm also getting this same issue of no USB mouse / keyboard (all types) with my 8Gb version - straight from fresh SD card image - linuxcnc-2.8.0-pi4.img

Any ideas of how to fix?

This is not a power issue (that has been previously noted), running of 7A SMPS and also tried with 20Ahr battery pack with same result.

When plugging in usb mouse, the red sensor led lights up briefly before going out (all 4 usb ports).

Unable to set up remote access so impossible to generate any kind of dump.

i've made a separate thread to avoid clogging this one up

forum.linuxcnc.org/9-installing-linuxcnc...-on-raspberry-pi-8gb

I'm also getting this same issue of no USB mouse / keyboard (all types) with my 2Gb version - straight from fresh SD card image - linuxcnc-2.8.0-pi4.img

"Do you have the same problem with a standard Raspbian install, or is it just the LinuxCNC image?"

Raspbian works fine with keyboard and mouse. So it seems that it is "just the LinuxCNC image"

I will try a 4GB hence it seems to be working straight away.

Bought the 4gb version, and it booted right up

I have both a Rpi 4 B 2G & Rpi 4 8G and have this problem. So far I have tried using the 2.80 & 2.81 Images and get the same results no matter which Pi or version I use.

I have the same problem with both versions, so 2.8 and 2.81.
I tried it on Raspberry pi 400 and RPi 4B+ 4Gb.
Either the system freezes immediately after the restart following the notification: resize file system.
This is preceded by a message: Error: cpu 0 not supported
Or the system freezes as soon as the desktop is displayed.