I have a 2012 MacBook Pro Retina (15inch) which I've had since late 2012, and I've got a bit of a strange problem with it. About 2 months ago, I hadn't used my MacBook in weeks, but it was left on sleep (just closing the lid). When it came to trying to use it, it was dead. I presumed it needed charging so I left it on charge overnight, but when I woke up the charger light was still orange which I found strange. Sure enough when I tried to turn it on it still wouldn't power on - the screen stayed off and there was no signs of life in it at all. I tried to make an appointment at the Genius Bar but all appointments were taken, so being fairly tech-minded I decided to open the laptop up to check for loose connections etc. I soon discovered it was all very unmaintainable so I didn't do anything, other than blast it with some compressed air to remove some dust. There were still no signs of life, but 2 days later I tried it again just out of curiosity and it booted up perfectly, with ~30% battery! Now I've stupidly done the same thing - left it on sleep for a couple of weeks, and then tried to use it again to discover it doesn't power on. The charger never turns to 'green' to indicate it's fully charged again, and even when charging overnight the underside doesn't feel warm at all. I've tried an SMC reset (also tried this last time I had this problem) to no avail, all it does is temporarily turn the charger light green. Has anyone experienced this? The obvious solution is to either get it sent off to Apple or go to the Genius Bar, but I want to exhaust other options first as I don't have AppleCare and want to avoid paying too much for this! Thanks!