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System sleep in OS X is a convenient feature that saves power while preserving your work flow. This option has been available in Macs and other PC systems for years, and is especially useful for laptops where you might wish to conserve battery power. While computer sleep is nothing new, there are some details of how it is implemented in OS X that may help you troubleshoot situations where sleep does not behave as it should.

For Mac systems sleep is governed by the system management controller (SMC), which has a number of variables it uses to manage when disks … Read more

Most troubleshooting for Mac systems revolves around software-based problems, be it bugs in the system software or a faulty OS configuration or installation; however, sometimes errors can extend beyond the operating system to the hardware itself, and when this happens, you may see no activity when starting up your system. However, even though the system may appear dead, it might have some indications of the problem at hand.

In the Mac's startup sequence the first step that occurs when you press the power button is all components such as hard drives, video cards, I/O controllers, and add-in cards … Read more

Apple has issued a firmware update for its latest Retina MacBook Pro systems that adds support for the new PowerNap feature in OS X Lion.

PowerNap allows the system to save energy by maintaining Sleep mode but still allow the system network access for updates and synchronization, as well as allowing backups to happen in the background. This feature is only available on the 2011-2012 MacBook Air systems and in the MacBook Pro with Retina Display; however, these systems did require a firmware update to use the new feature.

Apple issued the required firmware updates for the MacBook Air systems … Read more

The OS X 10.7.4 update that Apple released yesterday has been a relatively smooth update for many people, and is a recommended update because of its fix for a password logging error and the ability to preserve users' preferences for whether to open windows when logging back in. However, a few people have found that this update causes massive number of kernel-related error messages to be displayed in the system console.

As described by Apple Discussion member "paddyiyer", after updating the following messages can be seen repeated in the Console utility:

5/9/12 7:20:… Read more

Sleep modes on Mac systems are convenient for saving power while preserving your workflow, and can be set up in the Energy Saver system preferences for various power schemes (batteries, power adapters, and UPS units).

The system should stay in sleep unless specifically commanded to wake; however, there are times when the system may randomly wake from sleep. This can be irritating because it wastes power, especially for laptop batteries; however, it can also be concerning for those who might wonder if their systems are being accessed.

Though systems generally wake up because of user input (clicking a mouse or … Read more

Apple has released an update for its latest MacBook Pro systems that resolves an issue where systems running under wall power may unexpectedly shut down under heavy workload if the battery is at low levels. Apple does not specify exactly what revisions of the MacBook Pro this update is for, but it will only install on those for which it applies.

The update is a small 730KB download either from Software Update or from the Update's Web page, and requires OS X 10.6.8 or OS X 10.7.2 or later. The update will require you to … Read more

Putting a system to sleep is far more convenient than shutting it down between uses, because it allows you to save the machine's running state, to quickly pick up from where you left off without having to load the OS and programs again. While sleeping is usually a fairly quick process, sometimes problems can occur that cause it to take a long time or even hang. In these cases, even if you close a laptop's screen the system will stay running, and will then either just continue to run normally or not respond to any user input.

Unfortunately, … Read more

Sometimes after running a system update, be it a security patch, an incremental OS update, or a full upgrade to a new OS version, you may experience problems with the system's fans running loudly. This may happen immediately and continuously after updating the system, or it may be an intermittent but frequent occurrence. Sometimes this can be coupled with system slowdowns, but at other times it may seem to happen with no other apparent effects.

There are several reasons why this can happen, including corrupt hardware settings, corruption in software configurations and temporary files, and a fault in the … Read more

After updating your OS you may find a number of small issues with programs not functioning properly or some system services not working. As we noted earlier, some people have had difficulty with iTunes freezing after updating to OS X 10.6.7, but in addition some other people have found their Bluetooth devices such as the Magic Mouse and Magic Trackpad have not been able to connect.

When these types of issues occur, sometimes basic resets can clear the problem and cause the system to properly recognize the available services. The basic resets are to restart the computer (using … Read more