Bootup

Q&A: MacFixIt Answers

MacFixIt Answers is a feature in which I answer Mac-related questions sent in by our readers.

This week readers ask about how to swap an iMac's hard drive for a solid-state drive, what specifically Thunderbolt and FireWire ports are for, how best to transfer large files between Macs, and what to do about an iMac that no longer boots after a power outage.

I welcome contributions from readers, so if you have any suggestions or alternative approaches to these problems, please post them in the comments!

Question: Swapping an iMac's hard drive for an SSD MacFixIt reader Dave … Read more

How to address a constant reboot loop in OS X

When you start up your Mac, the system will generally show a gray Apple logo for a brief period followed by the log-in screen or other user interface elements as the rest of the operating system loads. In some instances, after crashes, power outages, or changes are made to the system, instead of booting properly the system might display the Apple logo and then reboot, repeating over and over.

Once the OS X kernel loads properly, even if there is a problem with background services, the computer will still boot but will just display unwanted behavior such as location services … Read more

Boot argument options in OS X

When you boot a Mac system you have the option to supply keyboard commands at startup to boot the system to alternate environments. For instance, a common option is to hold the Shift key to boot to Safe Mode, but you can also hold Command-V for verbose mode (a text output of items as they load), or Command-S for Single User mode, which drops you to the command line as the "root" user so you can perform troubleshooting tasks.

In addition to keyboard commands at startup, you can use the "nvram" terminal command to set a … Read more

Q&A: MacFixIt Answers

MacFixIt Answers is a feature in which we answer questions e-mailed in by our readers.

This week people wrote in with questions how to manage corruption in the EFI boot loader in OS X or manage disks without one, the necessity of the OS X "periodic" scripts and whether or not they need to be rigorously scheduled, and a sudden instance where the desktop and screen contents appear larger than the size of the screen itself. We continually answer e-mail questions, and though we present answers here, we welcome alternative approaches and views from readers and encourage you … Read more

Troubleshooting the boot process for Intel Macs

A number of events happen when you boot your Mac that activate the hardware and load the system software. Understanding these and some of the behaviors that the system might show when problems occur during these steps can help determine what you should do if your system will not boot properly.

Powering up Upon pressing the power button on your system, computer components such as hard drives, add-in cards, and other controllers receive power and start initialization routines to ensure that their hardware is working OK. If these components are all in working order, then they will assume a "… Read more

Inability to boot to Safe Mode in OS X

When troubleshooting various aspects of OS X and Mac hardware, one common routine is to boot into Safe Mode to automatically run some maintenance routines and prevent the system from loading inessential features. This can be done by holding the Shift Key immediately after hearing the boot chimes when starting the system up; however, sometimes this may not work.

Booting to Safe Mode requires the Mac's firmware to send the kernel some variables (boot arguments) that it interprets as a command to modify the procedures it uses to load the rest of the system. These can be set manually … Read more

Devices not loading properly at boot in OS X

There may be instances in OS X where devices that require a third-party driver (such as input devices and cameras) will not properly load at bootup. While a device may load when attached to the system after bootup, it may not be recognized properly when attached at during startup. When this happens, it is usually a problem either with the system's boot caches, or a problem with the developer's configuration of the driver being used for the device.

One way developers create drivers in OS X is to start with a generic driver class (i.e., a "… Read more

Basic troubleshooting steps for a Mac that will not start properly

While full system crashes that result in a nonfunctional system are relatively rare these days, they do periodically happen. If not the result from a direct crash, sometimes corruption can appear and suddenly cause an otherwise healthy system to no longer boot.

MacFixIt reader "sparkyrom" writes in with such a problem:

"My Macbook does not boot. It starts, the apple sign appears, the rotating sign appears, it stays like that for minutes and then restarts itself. What should I do? I tried resetting the SMC and PRAM but nothing happened. I did the Apple Hardware Test and … Read more

Startup speed up

There are few things more frustrating that an unwanted program that launches every time you start your computer, especially when the normal means of preventing this from happening--like checking for it in the Startup folder--don't work. What's worse is when numerous unneeded and invisible processes launch, slowing down both start-up and your computer's performance as a whole. AutoRuns is a simple program that lets users view--and disable--everything that runs on startup, saving both time and irritation.

The program's interface is a little cluttered, with 17 tabs that display the various programs and processes that run on … Read more