Driver | Acpi\sny5001

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."

A few years ago, I bought a used Sony VAIO laptop. It was a beautiful machine—sleek, magnesium-alloy body, a gorgeous 1080p screen. But within an hour of using it, I noticed a problem: the fan was always on. Not loud, just a constant, low whirrrrr that never stopped, even when the CPU was at 2% usage.

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

I installed it. It took 10 seconds. No reboot needed.

I searched online and found nothing but old forum threads. One said, "It's a dummy device, ignore it." Another said, "Your laptop will explode if you don't fix it." Very helpful. Then, deep in a 2012 VAIO support thread

"ACPI? That's power management stuff. SNY? That's Sony. 5001? No idea," I thought.

Right-click → Update driver → "Windows couldn't find drivers." Standard. But within an hour of using it, I

That's when it clicked. The fan wasn't broken. Windows simply didn't know how to control it because the driver was missing. The laptop was running a "safe mode" fan profile: ON all the time.