A couple of days ago my wife's V5-571 laptop developed an "interesting" feature where it would do an instant power-down when certain keys were pressed (in particular the "9" or "-" keys). Since her Windows password contained a 9, she obviously wasn't able to get very far. She now has a different password!
I removed the hard drive and put it in an external enclosure, and ran a SmartCtl test which showed no errors. I've also run MemTest86 to check the memory, also with no errors reported. At present the laptop has an external USB keyboard attached, just in case the problem in some way relates to the built-in keyboard; so far the problem hasn't shown up today.
Windows EventViewer doesn't show anything obviously relevant - just a "Critical - previous shutdown was unexpected" *after* rebooting.
A bit of history here. She got the laptop from a family member a couple of years ago, with Windows 8 installed, and without any of the original supporting media. I upgraded it to Windows 10 about 18 months ago, and it's been working fine until this started happening a couple of days ago. Has anyone seen anything of a similar nature? Any ideas what I might try next? So long as the problem never shows up with the external USB keyboard - and it hasn't yet - I guess we can live with that, but it would be nice to fix it properly.
