Acpi\sny5001 Driver -

Then, deep in a 2012 VAIO support thread (archived, in Italian), I found a real clue: "SNY5001 is the Sony Firmware Extension Parser. Without it, Windows can't talk to the EC (Embedded Controller) for fan curves and battery health."

I went back to Device Manager. The yellow triangle was gone. had moved to "System devices" and was now named Sony Firmware Extension Parser . acpi\sny5001 driver

Right-click → Update driver → "Windows couldn't find drivers." Standard. Then, deep in a 2012 VAIO support thread