For over a decade, I was running my home server on a trusty AMD Athlon II X4 PC, without any issues.
After upgrading to a newer motherboard the retired one was left unpowered for several months. Then when powering it up, Linux would not boot on it no matter what I tried.
Various distros were attempted, including Xubuntu desktop, and Finnix (highly recommended for testing and troubleshooting from the command line). The symptoms were the same: the PC reads the media, then the screen flickers and goes black with nothing on it.
Using the boot command line of Linux, I was able to remove the "quiet" option to see where exactly does the boot freeze. To edit the boot command line, you can use these methods on Finnix (press TAB for BIOS or 'e' for UEFI), or these on Ubuntu (press down arrow, then F6).
That finally showed where the PC freezes while booting the Linux kernel:
pci 0000:00:15.0: bridge configuration invalid ([bus 00-00]), reconfiguring
Searching on this message's text only produced discussions on the kernel patch around that code, and no further useful information that would help diagnose and solve the issue at hand.
The final workaround for this was to go into the BIOS, under Integrated Peripherals, then disable one device at a time to see if booting fails the same way.
In this case, it was the On-Board LAN controller. Once this was disabled in the BIOS, everything worked as expected.
By posting this brief article, I am hoping that it will save someone the amount of time that I spend trying to diagnose and workaround this problem.