Monthly Archives: August 2012
If you’ve upgraded to Mountain Lion and traded swift wifi and fast Safari for a flakey internet connection and sluggish browser, you are not alone. Widespread reports of problems with wifi, Safari and Mountain Lion have been mounting ever since July 25th. However, unlike the lengthy debacle with similar wifi problems experienced after the Lion upgrade last year, a lot of users are finding their problems can be solved by using one or more of the tips below.
1. Create a new location and renew the DHCP lease
OS X Daily have a step-by-step procedure here
that is proving hugely successful. Don’t forget to follow their second step about changing the MTU value while you’re at it.
2. Reset default system preferences
If that didn’t do it for you, it’s time to roll up your sleeves and enter Terminal! Open the Terminal.app from
and paste this command
then press ‘return’.
You will need to restart your mac to see if this has had any beneficial effect, so do that now.
3. Do PRAM & SMC resets
If you’re still suffering problems, it’s time for a couple of system resets. To do the SMC reset you will need to see what kind of mac you have, as the procedure is different for some models. Take a look here and follow the instructions for your model.
Before powering up after the SMC reset, also take the trouble to do a PRAM reset. To do that:
i. Ensure the machine is powered off.
ii. Locate the following keys on your keyboard in preparation for Step 4:
‘command’ – ‘option’ – ‘P’ – ‘R’
iii. Press the ‘power on’ button.
iv. Immediately – and before the grey screen appears – hold down ‘command-option-P-R’ all together.
v. Keep them held down until you’ve heard the start-up chime twice. After you release them you should hear it again, and hopefully your Mac will boot up without wifi/Safari issues.
4. Check Wifi connection
And if that doesn’t work? Time to check your wifi connection. See how strong your signal-to-noise ratio is. You need something in the order of 25 or higher. To find out whether you signal is strong enough, hold down the ‘option’ key and click on the wifi icon in the menu bar. Choose Open Wifi Diagnostics from the menu.
When you see the welcome screen, ignore the ‘Continue’ button and instead press ‘command-N’ on your keyboard.
Click wifi scan in the task bar and scroll to the right where you will see two numbers, ‘signal’ and ‘noise’. Ignore the minus ‘-‘ signs, and subtract the signal number from the ‘noise’ number. Anything over 25 is a good enough signal, below that and the signal is too weak for a reliable connection. Over 40 is excellent (in the example below, you can see the SNR is 34, a pretty good signal for a home router located on the next floor).
If your SNR is lower than 25 you need to either move the computer closer to the router or find a better connection. If the ‘Noise’ shows a very low figure (equals more noise), you can try changing the channel on your router. Look at the other routers in the list and if they are using the same channel as yours, switch your router to something else between 1 and 11.
5. Reinstall OS X
If all else fails…some users are reporting that simply reinstalling OS X is solving the problem for them. Reinstalling doesn’t touch your Apps or user data, but its always wise to make sure you have a backup before undertaking such an operation.
To reinstall, restart the computer while also holding down ‘command-R’ on the keyboard. From the Utilities window that opens up, choose ‘Reinstall OS X’.
Still having problems? Let us know in the comments below.
featured picture: Internet by ~vagraine
One of the features I really love in OS X is the ability to preview anything by selecting the file in finder and pressing the spacebar – formally called ‘Quick Look’ – without actually having to open the full app. This is great for both music and movies.
However, if you uninstalled Perian or Flip4Mac or haven’t updated them recently, you will find that a lot of movie files – like .avi, for example – which are not fully supported in QuickTime won’t preview. The answer is to get the latest versions of these two plug-ins:
(hit the green download button (free), ignore the one trying to sell you a paid version).
You should then be able to see any movie using Quick Look.
QuickTime won’t play my video
To find out which model of mac you’ve got, hold down the option key on your keyboard and select
> About This Mac
Check the ‘Model Identifier’ against this list:
Of course, just because your machine’s listed, it doesn’t mean it will necessary meet all the specifications, so be sure to check the tech specs too.