You thought that power outage during flashing had nuked for good your system, but the reality is that modern PCs all have a flashback function (unless that has also been killed, like that one time that I tried to hack my laptop and downgraded the non-downgradable EC firmware 🙃)
This can also (only sometimes?) be used to update the BIOS version in order to support newer CPUs, even without any one installed at all.