On powering up, a kind of green, slightly pixelated Mac icon and boot up progress bar appears. It takes forever for the bar to finish then the screen goes to not pure white but kind of a magenta toned white, then it goes to black then the whole thing starts over again. I've tried holding D during boot up, then command R during another round and finally shift during another round. Nothing works, it just keeps going over and over again. BTW I don't hear the chime when it starts, it just goes into this mode and infinite loop. I wish I remembered the stats of my laptop but I don't know them off hand. I know I'm NOT running Sierra, I'm pretty sure it's Yosemite but might possibly be El Capitan. It's a MacBook Pro from like 2011 or 20012. There is a little bit of moire patterning from my phone's shot of the screen but hopefully you can see what's going on. Any help is appreciated.