What can you do if your Mac randomly crashes or kernel panics?

Random crashes and kernel panics (when the screen goes dark and you're told to restart) could be down to hardware going wrong. Check things aren't getting too hot - are any of the air vents filled with dust?

A utility such as iStat Menus will enable you to see how hot different parts of your Mac are running. Every model is different, but unless you're doing some really intensive work, it shouldn't be going above 80°C.

Next, check your RAM is seated properly by removing it and plugging it back in, and run the Apple Hardware Test by inserting your Applications Install DVD and restarting while holding down D.

If this finds no trouble, you could work through crash logs to pinpoint what might be causing it, but we suggest, you back up your hard drive, erase it and reinstall OS X.

"Everything's slowing down on my entire Mac!"

Dashboard

When you've experienced your Mac at its speedy best, slowdowns can be unbearable, but there are several things you can do.

Have a look in your Applications folder and see if there's anything there you no longer use Using an uninstaller app such as AppDelete, AppZapper or CleanMyMac, removes anything superfluous. This will also free up space for Mac OS X to use as virtual memory.

If your boot drive still has less than 10GB free, it's a good idea to move some files elsewhere to enable the OS to perform to its best. Why not put your media on an external drive?

Now press F3 to open Dashboard, hold down Option, hover over any widgets you don't use and click the x to get rid of them - they put strain on your Mac.

A more extreme way to get your Mac back to its best is to back it up and then reinstall OS X, but don't then use Migration Assistant, as this could bring the problem with it. You'll need to copy your files across manually.

Lastly, think about how old your Mac is. As software becomes more demanding, older machines will slow down when they run it.

"My keyboard has a faulty key. How can I fix it?"

If a key on your keyboard won't press down, it's likely there's something stuck under it. Every keyboard tends to be different, but with the recent Apple ones, you can prise the key off and give it a clean underneath, then clip it back in again.

However, if you do this, it is entirely at your own risk!

"My mouse doesn't track or scroll properly"

It probably needs a good clean! Dirt and grime can build up on the bottom of a mouse over time, so scrape it off gently. To clean the scroll ball in a Mouse (formerly Mighty Mouse), roll the ball over some sticky tape to clean it.

How to reset the SMC

Reset smc

If your Mac's been running slowly or refusing to start up, resetting the System Management Controller (SMC on Intel Macs) or Power Management Unit (PMU, on PowerPC machines) sometimes helps.

The SMC or PMU control the power given to components in your Mac, and resetting it can solve certain problems. However, it's not a universal fix and Apple has a list of specific conditions when an SMC/PMU reset may be appropriate. Even then, it's a last resort.

The way to do it differs between models. For Intel-based Macs, have a look at this page for instructions on when and how to reset your SMC. And for older ones, check out this page and this page.

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First published in MacFormat Issue 234

Liked this? Then check out How to fix Mac startup problems

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