Same problem - must be a motherboard failure since Win10 never even gets a chance to log a serious or critical error. Just spontaneous shutdown.
I think the VAIO VJS142C11L is VAIO Corporation, no longer Sony.
* https://en.wikipedia.org/wiki/Vaio#Spin-off_from_Sony
There is a recent BIOS update for the VJS142 - although it's a really long shot for 2 reasons.
# When is the last time a BIOS update could fix something so substantial : )
# Flashing the BIOS with a laptop that spontaneously shuts down is a desperate move. I tried it ... and spontaneous shutdown while just 25% into the update. Brick. Anyone know a good way to repair a corrupt BIOS ;) ?
Good luck. Seems like VAIO Corp used a bad motherboard, or bad fabrication on these.