I once again turned to Google, but this time found no useful results, and was
forced to resolve the problem by myself.
I hypothesized that the prior BIOS change had - somehow - interfered with the
GPUs’ ability to perform “graphics” tasks. As a workaround, I decided to
reconfigure my BIOS to use the processor’s “integrated graphics” to drive the
I booted into BIOS config and did the following:
Navigated to Settings\Advanced\Integrated Graphics Configuration
Set Initiate Graphic Adapter to [IGD]
I rebooted the system. Video output was now fine while booting, but became
“fuzzy” after the X server started. I had one final problem to solve.