laptop is new; used less than 2 weeks.
as usual i had 4 or 5 tabs open on firefox, one of them streaming music
i wasn't at that time "using" the laptop; i suddenly heard a loud, abrasive, buzzing sound
looked at the screen - it had gone dark
it didn't respond, so i forced shut it.
when i restarted it, it worked without any hitches.
i am concerned about that loud buzz - there was no heavy programs running on the laptop.
i don't play games. just web browsing, writing, & streaming music.