Mac Pro (Late 2013) continually crashes.

My Mac Pro (Late 2013) is running 10.10.5 OS X Yosemite. It continually crashes. Here are the facts:

• The computer is hooked up to a WXGA TV Display. It is a non name-brand display.
• The computer freezes when:
  • It is streaming video

    Chrome Browser

  • Playing any sort of video located on my SSD or external drives.
    • iTunes
    • Quicktime
    • GoPro Studio
• The screen will freeze, the sound will continue to play, and the rainbow wheel shows up.
• The problem is intermittent. It happens randomly but only in regards to the bullet points above.
• It has never frozen when reading articles or playing music.
• Keyboard commands are unresponsive
• I have to shut the computer down manually by holding the power button

I am at a loss as to what would cause this. Any insight would be greatly appreciated.

Thanks!