I have a mid-2012 13" MacBook Air that for 3 weeks has had Kernel Task using 100% of the CPU at startup with nothing running...for anytime between 2-8 hours!!! This makes the computer virtually unusable. I've tried several things (such as one home remedy found online where users moved the model identifier .plist file out of the Extensions folder, as well as an OS clean install). I've also been to 2 Genius Bar appointments where they ran their hardware diagnostics, cleaned out the dust from the back of my logic board, and tried replacing the battery (battery doesn't work and has an 'X' on the indicator but when they replaced it it still had an X, making me think it's the connection to the board that's broken). Anyways, nothing has worked. At the last appointment they offered me a flat fee repair where they ship it out to depot and fix everything wrong with it, for $425 or $475 (I can't remember exactly). I have a screen with several dots around the Apple logo that could use some fixing, a broken battery connector (and or mother/logic board) and this kernel task issue. I was wondering if anybody could weigh in on whether this is worth it. I was really against paying for the repair since I have so many expenses (I'm getting married in 2 months) but my computer is completely non mobile and on some days completely non usable. Thanks!!