This computer had damaged casing when we got it, but it was "refurbished" and "Apple Certified" so we thought it would still be ok, but by December 20, after 3 months, it simply stopped charging or turning on. Did troubleshooting.  Called Apple services. Visited the Apple store.  No luck. They can't do a diagnostic on a dead computer. This is a very expensive brick. I don't advise to order refurbished computers from Amazon.