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guykuo Author

Level 1

44 points

Thermal Stress Test All MacBooks for Peace of Mind

Given the now documented propensity of some MacBooks to melt the insulation of a thermal sensor wire and develop random, intermittent shutdowns after a month or two of normal usage, I think it advisable for all MacBook owners to test their machines and expose any weakness while it is WITHIN warranty. A newly purchased MacBook probably should be thermal stress tested well before the 14 day replacement period expires.

Opening terminal and running yes in two windows maximizes CPU utilization and temperature. Several overnight runs or a 24 hour run without arranging extra ventilation should expose any MacBooks that are physically prone to melting their thermal sensor wire insulation. The goal of the run is to heat the heatsink to as high a temperature as it will ever experience and hold it there for several hours. If the insulation holds, it should continue to do so. If it melts, the machine will start experiencing intermittent shutdowns during normal use.

A few days of normal usage after that session would give good peace of mind that the machine is less likely to fail later. Intentionally thermal testing early gives owners a better chance to have a fault prone machine repaired under warranty or replaced.

This would also be useful for newly repaired MacBooks prior to putting them back into critical usage.

macbook, Mac OS X (10.4.7)

Posted on Oct 7, 2006 8:16 AM

20 replies

Oct 7, 2006 11:45 PM in response to guykuo

I beleive this test is VERY valid. I do lots of video rendering overnight all the time. All the MB ( 15 Macbooks, and counting !!! ) that i tried the nul test on failed at one point during the test... and sure enough, within days or weeks they ALL develop the RSD.
I'm presently using a loaner from the store, it's a week 26...and i put it through the nul CPU test for 36 hours straight ...no problem. Beside the test, the machine has also been doing Mpeg2, AC3 rendering for 8 hrs every night for the past 2 weeks..no problem.

guykuo Author

Level 1

44 points

Oct 9, 2006 11:58 AM in response to tutudrummer

According to Think Secrets http://www.thinksecret.com/news/0908macmini.html

"Apple recently notified service providers that customers who report experiencing the random shut-down problem should submit their systems for evaluation and that Apple will replace the faulty parts in systems deemed affected by the flaw. Parts affected by the issue are said to include the logic board and heatsink."

All the more reason to actually test your MacBook now and see if it is prone to intermittent shutdown.

Oct 9, 2006 12:51 PM in response to tutudrummer

maybe they all developed RSD because you stressed them out beyond what they're supposed to be stressed.

listen people, that's like saying a new porsche should be run at 200 miles an hour for 24 hours straight after you buy it. no one in their right minds would do that. how's that different from this?

just because a machine CAN do something doesn't mean it SHOULD do so for an extended period of time.

guykuo Author

Level 1

44 points

Oct 9, 2006 1:16 PM in response to MuadDib420

You're basically then saying that MacBook owners should never run a high CPU usage application for an extended period of time? Running yes would not be any more stressful than doing fairly mundane Mac tasks like...

Video encoding and compression
3D Rendering
Animation rendering
Playing games with lots of physics simulations.

No.... that is absurd for a modern machine that has the ability to regulate its CPU speed and cooling fan. It should never overheat to destruction. If yes sessions seem too "severe" then at least let it do a something that uses a lot of CPU to bring out any inherent weakness in the early machines BEFORE they go out of warranty.

zplus

Level 2

230 points

Oct 9, 2006 1:56 PM in response to guykuo

How about putting in a dvd and set it on loop, put the screen to full brightness and speakers in full, and then leave it running over night for as long as it takes for any part of the MB to break. And get a baby (borrow one if you dont have one yourself) to test type the keyboard till one of the keys cracks.

O and while you are at it, get a cat to test the cover plastic and see how long it wud take them to scratch up.

And if all the above tests goes well, then u can use ur MB without any worries in mind.

Thermal Stress Test All MacBooks for Peace of Mind