Regardless of what went inside it I cannot see Sony not covering it, it's under 1 year. Best thing to do would be to check with them first, prior to doing anything that might actually void your warranty.
These days consoles are too expensive and unreliable (first batches that is) to be opening them up and voiding the warranty for my liking.
That being said, whoever mentioned the possibility of a blown fuse on the power supply is probably on the right track. I would explain the 'pop' sound. Google searching seems to indicate the power supply does indeed have a fuse. According to this document (attached below) it appears to be fairly simple to replace as well. Of course, I am not saying this document is 100% accurate, and following it would be something you do at your own risk... like I said earlier, I'd try and go through Sony first.