I have a low-end Toshiba C55Dt-A5305 that has recently begun exhibiting a very odd behavior: shutting itself down, but "gracefully," without any user intervention.
The Windows Update settings were initially fully automatic, so when this started I attributed it to updates having been applied that required a restart and that restart being done, but that's not it. Since that time I've changed the setting to "download but let me choose when/whether to install" and then even to "check for updates, but let me choose whether to download and install" and it hasn't made one bit of difference.
When the machine shuts itself down it isn't "sudden death" like the old-style BSOD or an instant shutdown from overheating. It seems to happen at random times, more often overnight than during the day, but it's sometimes when you're in the middle of something or when the machine is just sitting there, idle.
I really don't have the first idea of how to track down what might be causing this behavior. Any assistance would be very appreciated.