Chapter 22
In This Chapter
Avoiding the blame (righteously)
Putting basic troubleshooting precepts to work
Using Mark’s Troubleshooting Tree
Getting help
I wish you weren’t reading this chapter.
Because you are, though, I can only surmise that you’re having trouble with your iMac and that it needs fixing. (The other possibility — that you just like reading about solving computer problems — is more attractive, but much more problematic.)
Consider this chapter a crash course in the logical puzzle that is computer troubleshooting: namely, the art of finding out What Needs Fixing. You also see what you can do when you just plain can’t fix the problem by yourself.
Oh, and you’re going to encounter a lot of Tips and Mark’s Maxims in this chapter — all of them learned the hard way, so I recommend committing them to memory on the spot!
Anyone can troubleshoot. Put these common troubleshooting myths to rest:
Don’t beat yourself up. Your iMac can be fixed.
With those myths banished for good, you can get down to business and start feeling better soon.
In this section, I walk you through my Should-Be-Patented Troubleshooting Tree as well as the Mavericks built-in troubleshooting application, Disk Utility. I also introduce you to a number of keystrokes that can make your iMac jump through hoops.
Yep, it sounds silly, but the fact is that rebooting your iMac can often solve a number of problems. If you’re encountering these types of strange behavior with your iMac, a reboot might be all you need to heal
To put it succinctly, here’s a modest Mark’s Maxim:
Try to save all your open documents before you reboot. That might not be possible, but try to save what you can.
If you need to force a locked application (one that’s not responding) to quit so that you can reboot, follow these steps to squash that locked application:
The dialog that you see in Figure 22-1 appears on your screen.
If you can get everything to quit, you should be able to click the Apple menu and choose Shut Down (not Restart) without a problem.
If your iMac simply won’t shut down (or you can’t get the offending application to quit), do what must be done:
You have to wait about four seconds for your iMac to turn itself off.
After everything is back up, check whether the problem is still apparent. If you use your iMac for an hour or two and the problem doesn’t reoccur, you likely fixed it!
A number of keys have special powers over your iMac. No, I’m not kidding! These keys affect how your iMac starts up, and they can really come in handy whilst troubleshooting.
You can use Safe Boot mode to force OS X Mavericks to run a directory check of your boot hard drive and disable any Login Items that might be interfering with Mavericks. Use the Shut Down menu item from the Apple () menu to completely turn off your iMac; press the Power button to start the computer. Then press and hold down the Shift key immediately after you hear the startup tone. After Mavericks has completely booted, restart your iMac again (this time without the Shift key) to return to normal operation.
Table 22-1 provides the lowdown on startup keys. Hold the indicated key down either when you push your iMac Power button or immediately after the screen blanks during a restart. (As I just mentioned, the Shift key is the exception; it should be pressed and held down after you hear the startup tone.)
Table 22-1 Startup Keys and Their Tricks
Key |
Effect on Your iMac |
C |
Boots from the CD or DVD that’s loaded in your optical drive (if you have one) |
Media Eject |
Ejects the CD or DVD in your optical drive (if you have one) |
Option |
Displays a system boot menu, allowing you to choose the operating system and startup volume |
Shift |
Prevents your Login Items from running; runs a directory check |
T |
Starts your iMac in FireWire or Thunderbolt Target Disk mode |
+R |
Boots from the Mavericks Recovery HD |
+V |
Show OS X Console messages |
+S |
Starts your iMac in Single User mode |
+Option+P+R |
Resets Parameter RAM (PRAM) and NVRAM |
Some of the keys/combinations in Table 22-1 might never be necessary for your machine, but you might be instructed to use them by an Apple technician. I’ll warrant that you’ll use at least the +R startup key fairly often.
The Mavericks Disk Utility is a handy tool for troubleshooting and repairing your hard drive. You can find it in the Utilities folder within your Applications folder.
Fire up Disk Utility, click the volume that’s giving you a headache from the list at the left side of the window, and click the First Aid tab to bring up the rather powerful-looking window shown in Figure 22-2.
In the left column of the Disk Utility window, you can see
You can always tell a volume because it’s indented underneath the physical drive entry.
For example, Figure 22-2 shows that I have one 1TB internal hard drive and one 500.11GB external hard drive. The internal hard drive has three volumes (Wolfgang, Johann, and Ludwig), and the external drive has one volume (Time Machine Backups).
Because Mavericks is built on a Unix base, lots of permissions can apply to the files on your drive — that is, who can open (or read or change) every application, folder, and document on your hard drive. Unfortunately, these permissions are often messed up by wayward applications or power glitches or application installers that do a subpar job of cleaning up after themselves. And if the permissions on a file are changed, often applications lock up or refuse to run altogether.
Use these steps to repair permissions on your iMac’s hard drive:
Chapter 20 shows you how to log in as an admin user.
Alternatively, click Go⇒Utilities.
You can repair permissions only on a boot drive.
I don’t worry about verifying. If something’s wrong, you end up clicking Repair Disk Permissions, anyway. Just click Repair Disk Permissions; if nothing pops up, that’s fine.
This last step allows you to see whether a problem has been corrected!
Disk Utility can check the format and health of both hard drives and volumes with Verify Disk — and, if the problem can be corrected, fix any error with Repair Disk.
If you have an external drive connected to your iMac that has a Mavericks boot volume, you can boot from the OS X installed on the external drive to check your current startup disk. Or you can boot your system from the Recovery HD partition and run Disk Utility from the menu. (To choose the startup volume, open System Preferences and click the Startup Disk icon, or restart your iMac and hold down the +R startup key shortcut to boot directly to the Recovery HD partition.)
Using one of these methods, you should be able to run Disk Utility and select your boot hard drive or volume, and the Verify Disk and Repair Disk buttons should be enabled.
If your iMac is having trouble reading a CD or DVD, wipe the disc with a soft cloth to remove dust, oil, and fingerprints. Should that fail, invest in a disc-cleaning contrivance of some sort.
If you need to verify and repair a disk or volume, follow these steps:
As the hip-hop artists say, “All right, kick it.” And that’s just what my iMac Troubleshooting Tree is here for. If rebooting your iMac hasn’t solved the problem, follow these steps in order (either until the solution is found or you run out of steps — more on that in the next section).
This is a simple step that many novice Mac owners forget. Simply retrace your steps and consider what changes you made recently to your system. Here are the most common culprits:
If you didn’t make any significant changes to your system before you encountered the problem, proceed to the next step.
The preceding section shows how to repair disk permissions on your Mavericks boot drive.
Cables work themselves loose, and they fail from time to time. Check all your cables to your external devices — make sure that they’re snug — and verify that everything’s plugged in and turned on. (Oh, and don’t forget to check for crimps or even Fluffy’s teeth marks in your cables.)
Check the contents of your Trash to see whether you recently deleted files or folders by accident. Click the Trash icon on the Dock once to display the contents. If something’s been deleted by mistake, drag it back to its original folder and try running the application again.
I know this one from personal experience. A slight miscalculation while selecting files to delete made an application freeze every time I launched it.
Now that always-on DSL and cable modem connections to the Internet are common, don’t forget an obvious problem: Your iMac can’t reach the Internet because your ISP is down, or your network is no longer working!
A quick visual check of your DSL or cable modem will usually indicate whether there’s a connection problem between your modem and your ISP. For example, my modem has a very informative activity light that I always glance at first. However, if your iMac is connected to the Internet through a larger home or office network and you can’t check the modem visually, you can check your Internet connection by pinging www.apple.com, as follows (see Figure 22-4):
You should see successful ping messages similar to those in Figure 22-4. If you don’t get a successful ping and you can still reach other computers on your network, your ISP is likely experiencing problems. If you can’t reach your network at all, the problem lies in your network hardware or configuration.
If you made it to this point, it’s time to run a full virus and malware scan — and make sure that your antivirus application has the latest updated data files, too. My antivirus application of choice is Virus Barrier 2013 from Intego (www.intego.com). (If a virus is detected and your antivirus application can’t remove it, try quarantining it instead, which basically disables the virus-ridden application and prevents it from infecting other files.) I can also recommend ClamXav 2, the antivirus application from www.clamxav.com. (If you like ClamXav 2, you can send a donation to the author.)
OS X might encounter problems with applications that you’ve marked as Login Items within System Preferences. In this step, I show you how to identify login problems and how to fix ’em.
It’s time to use another nifty startup key (refer to Table 22-1). This time, hold down Shift after you hear the startup tone.
This trick disables your account’s Login Items, which are run automatically every time you log in to your iMac. If one of these Login Items is to blame, your iMac will simply encounter trouble every time you log in.
If your iMac works fine with your Login Items disabled, follow this procedure for each item in the Login Items list:
You can delete the selected item by clicking the Delete button, which bears a minus sign.
When your iMac starts up normally with Login Items enabled, you discovered the perpetrator. You’ll likely need to delete that application and reinstall it. (Don’t forget to add each of the working Login Items back to the Login Items list!)
This is a long shot, but it isn’t unheard of to discover that a faulty, bug-ridden screen saver has locked up your iMac. (If you aren’t running one of the Apple-supplied screen savers and your computer never wakes up from Sleep mode or hangs while displaying the screen saver, you found your prime suspect.)
Open System Preferences, click Desktop & Screen Saver, click the Screen Saver button, and then either switch to an Apple screen saver or drag the Start slider to Never.
Ouch. You reached Step 9, and you still haven’t uncovered the culprit. At this point, you’ve narrowed the possibilities to a serious problem, like bad hardware or corrupted files in your OS X System folder. Fortunately, Mavericks provides System Information, which displays real-time information on the hardware in your system. Click the Apple menu and choose About This Mac, click More Info, and then click System Report. Figure 22-5 illustrates a typical healthy result from one of the Hardware categories, Graphics/Displays. Click each one of the Hardware categories in turn, double-checking to make sure that everything looks okay.
Don’t worry, friendly reader. Just because you’ve reached the end of my iMac tree doesn’t mean you’re out of luck. In this section, I discuss the online help available on the Apple website as well as local help in your own town.
If you haven’t visited the Apple iMac Support site yet, run — don’t walk — to www.apple.com/support/imac/intel, where you can find
In case you need to take in your iMac for service, an Apple Store or Apple Authorized Service Provider is probably in your area. To find the closest service, launch Safari and visit
Click the reassuring-looking Service button and choose Mac from the Select a Product pop-up list box to search by your current location, city and state, or zip code. The results are complete with the provider’s mailing address, telephone number, and even a map of the location!
Always call your Apple service provider before you lug your (albeit lightweight) iMac all the way to the shop. Make sure that you know your iMac’s serial number (which you can display in System Profiler) and which version of OS X you’re using.