I bought a Mac Mini for my mother 40 days ago. She didn't have any issues on 10.9.3. However, after upgrading to 10.9.4 she is having an issue. Occasionally on cold boot or restart the light comes on, but the it doesn't power on the monitor. The fan spins to its max and you have to force shut it down. What would cause this? I just tried a PRAM reset. If the issue persists I will try a SMC reset. If ALL that fails I will restore her to 10.9.3 with a boot drive I have. Anyone here have this issue?