Aurora R16, spinning blue circle on startup

I've owned the PC from new, purchased over a year ago. This is my work computer. A few months ago, there were major issues, and after a 16 day wait a technician came to the office and replaced the i9 processor. This fixed that, but then two days ago, three days after the warranty ended, another major problem. After installing a routine Nvidia driver update, after the customary blinking, the screen turned into a soup of swirling pixels with nowhere to click. Restarted the computer with the power button, and all seemed okay. However, at the end of the work day, the screen power off button did nothing. After trying several times, again re-started the PC. This time, the PC came on with just the small blue circle, which moves with the mouse.

Contacted Dell support, paid for direct talk with a technician, when through all the steps (can access the F12 boot options including recovery), but nothing has changed (and was refunded).

Which hardware is likely affected here? Is a complete OS reload likely to fix this?

Having lost over two weeks of work already this year through this PC, that there is yet another major issue, three days after the warranty expired, is pretty disappointing.