Why is my Mac acting up?

[luiso455]

For the first time ever, today my Mac has started to act up. I was on Skype with a friend, browsing the internet and rendering a video in MPEG Streamclip and my Mac started acting up and shutting down and turning back on. The first time this happened it completely shut-off and then second time this happened my screen went black and I had to hit the power button to get everything back to normal. Both times this has happened I was rendering in MPEG Streamclip so I have a feeling it might be that program.

Any tips or suggestions to fix this would greatly be appreciated, my Mac has NEVER given me a problem so this happening really scared me?

Could it be a software or hardware problem, I don't know you guys tell me?

Link to Youtube Video explaining and showing you guys the problem.


http://www.youtube.com/watch?v=R2oKoDuUkYs

 

[Moocher]

Heat? Download something to monitor the temp. I use smcfancontrol, as do many others. If you are running too hot you'll have to quit one of the heat-producing programs and/or turn up the speed on the fans. Running Skype while you are transcoding a video is asking a lot. Try one or the other.


Mooch

 

[Pax]

As Moocher says, it's possible there is a problem with the cooling system. But that would be a malfunction (eg fan broken). Your Mac should be able to handle anything you can throw at it - it should never overheat to the point of shutdown. The CPU can get hot when it's working hard, but the Mac's designed like that.

Try a temperature monitoring program (I use iStat nano) and post the temperatures when it's working hard. Also watch the temperatures as it approaches your shutdown point. Do not be surprised to see a CPU temperature around 90 C, and it might approach 105 C but not stay there fore more than a few minutes. Then the fans should start kick in and start working hard (around 3000-4000 rpm) to keep it at 90-95 C.

I suggest you don't try to mess around with the fan settings (eg using SMCfancontrol) yet. First you need to diagnose whether or not you have a major hardware problem which needs to be fixed by a trip to Apple. SMCfancontrol is more designed for people worried about CPU longevity to keep the CPU cooler than Apple designed. It's not designed to compensate for hardware problems.

You should be able to crank both cores and the CPU up to 100% eg playing a game, and have your Mac sit there quite happily indefinitely. (lots of flame wars on this forum about whether this shortens your CPU's life though - but we can get on to that later!)