I repair desktops and laptops, and I've diagnosed these symptoms as an issue with the GPU. I've recommended all of the owners to take it into an Authorized Apple Store to get them fixed or replaced with a newer model.

Read this:

https://www.apple.com/support/macbookpro-videoissues/

This post was edited by ChickenBakesOwn on Aug 22 2017 12:10pm