It’s been reported many times lately at Apple’s Discussion Board in the U.S., Japan and other countries that MacBook shuts down all of a sudden. Apple officially acknowledged in September 1 that MacBook has a shutdown problem. And you are requested to contact AppleCare if your MacBook experiences such problem. A sudden shutdown + portable Mac implies that it’s a heat problem that must be causing the CPU to stop clocking. Especially if you can restart MacBook after its CPU has cooled down, the cause must be heat. Actually, the problem is not that simply. One German blog writes this article, and the following is its rough English translation:

“Because the cool body of the processor expands after physical laws in the business, it knocks against the sensor cable so that the isolation melts. This leads to a short circuit – and the turning off of Apples of mobile Consumer-notebook. If the cool body cools off itself thereupon again and moves together around millimeter fraction, is banned the short circuit danger for the moment – to the moment where he expands in high processor load again and causes with the polished cable again a short circuit. Therefore a participation of the motherboard or defective RAM-component seems as a cause of the phenomenon unlikely. Concerned customers should address themselves in each case to an authorisierten Apple-partner for a possible repair.”

One quick solution is to use a slice of insulating tape on the heat sensor cable and keep it away from CPU’s heat sink. And this quick fix seems to work.