Why is my Macbook shutting down by itself?

[iMore Question]

Within the last year or so, my Macbook shuts down by itself for no reason. I've found this particularly so when in IMovie. But now it's starting to shut down for other reasons, i.e. when I close out a word document, or try to open a document. It's almost like when I do certain things, the computer decides it's either too tired or confused and just taps out!!

Help!

 

[Just_Me_D]

I don't know, but a trip to the Apple Genius Bar may be in order...

 

[photovary]

From your description of the problem, all of the operations are related to disk I/O, which is to write / read files. You can check your disk health first.

1. Launch Disk Utility, found within the /Applications/Utilities folder
2. Select the Mac hard drive from the left side menu and click on the “First Aid” tab
3. Click on “Verify Disk” in the lower right corner and let it run

You will find the window populating with messages about the drives health, messages that indicate things are fine appear in black, messages that indicate something is wrong appears in red.