Following recent contact between a major member of the media and Apple, it was revealed that Apple has today made a fix available for random shutdowns that will eliminate the need for customers to send their systems in for warranty service!
The fix takes the form of a SMC (System Management Controller) firmware update.
Jason Siebert, aka Sieb (thatsiebguy), who took the photo of the melted insulation featured on our demystified post points out that the shut downs may be caused NOT by an electrical short circuit problem but rather by the high levels of heat that the sensor cables are exposed to. Heat increases the resistance of the electric sensor cable and this results in a decrease in the current through the cable which in turns lead to altering the signal sent by the heat sensor (thermistor). If this signal indicates a high enough temperature, it is possible that the MacBook just shuts itself down to prevent any damage to the processor.
Thanks to some pictures of the MacBook heatsink on Flickr, the cause of random shutdowns in the 13″ MacBooks is now clearer! As previously thought, it is indeed an insulation issue. Here’s a close up of a melted heat sensor cable:
The area where the cable insulation melts actually houses a pair of cables and it is suspected that this is where the short circuit triggering a shut down occurs (when those two cables make electrical contact).
The tech news segment of Sky News, Technofile, from a few days ago addressing the issue of intermittent shut downs in MacBooks is now available as a video podcast from iTunes or as a download.
The podcast episode also includes a brief pros and cons discussion of PC vs Mac.
Download Link: Technofile Episode 6a
Last night’s Technofile, the techology segment of TV news channel Sky News featured the issue of MacBook Random Shutdowns.
The segment featured an interview with 3 affected MacBook owners: