Sunday the desktop screen was "faded" - would not go full on. Restarted the thing. Would not boot. Goes to Apple screen, then goes halfway (the bar), then shuts off or restarts. Repeats this over and over or just shuts itself down. Tried to boot off DVD - Command C - worked but problem repeated itself. And screen went all weird for a moment, then froze and then back to the "won't boot" loop and won't even come up with Command C off the DVD. Running El Capitan. Had no issues with this machine ever. Was watching videos with my wife, set it down and came back after shoveling snow and blammo! Any ideas before I take it to the Apple Store? Thanks!