Chapter 20
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, 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: the art of finding out What Needs Fixing. I tell you what to do when you just plain can’t solve the problem yourself.
Not surprisingly, you’re going to encounter a lot of Tips and Mark’s Maxims in this chapter. I learned all of them the hard way, so I recommend committing them to memory.
Anyone can troubleshoot. Believe it, and put these common troubleshooting myths to rest:
www.prosofteng.com
), but a third-party utility isn’t a requirement for troubleshooting. (I do, however, consider an antivirus application a must-have; you should have one already. Hint, hint.)With those myths banished, you can get down to business and start feeling better soon.
In the following sections, I walk you through my should-be-patented Troubleshooting Tree, as well as the macOS built-in troubleshooting application, Disk Utility. I also introduce you to several keystrokes that can make your iMac jump through hoops.
The simple fact is that rebooting your iMac can often solve many problems. If you’re encountering these types of strange behavior with your iMac, a reboot might be all you need:
To put it succinctly, here’s a modest Mark’s Maxim:
If you’re in the middle of a program, try to save all your open documents before you reboot. That might be impossible, but try to save what you can.
As your first (and best) option for shutting down, click the Apple menu and choose Shut Down. If you need to force a locked application (one that’s not responding) to quit so that you can reboot, follow these steps to quash that locked application:
Click the Apple () menu and choose Force Quit.
The dialog shown in Figure 20-1 appears.
When you 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:
Press and hold your iMac’s Power button until it shuts itself off.
You have to wait about 3 seconds for your Mac to turn itself off.
If holding the Power button down on your iMac doesn’t do the trick, press the Power button and the Left Option+Left Shift+Left Control keyboard shortcut at the same time; then release them all at the same time. (This method also resets some of your iMac’s internal hardware settings, which is often A Good Thing.)
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!
Several keys have special powers over your iMac. I’m not kidding! These keys affect how your computer starts up, and they can really come in handy while troubleshooting.
You can use Safe mode to force macOS to run a directory check of your boot drive and disable any login items that might be interfering with your system.
If your iMac has an Intel processor, follow these steps:
If your iMac has an Apple processor like the M1, follow these steps:
After macOS boots, you’re in Safe mode (the words Safe Boot appear at the right side of the Finder Menu bar), and you can check the operation of your iMac by using Disk Utility (or a commercial utility application). When you’re ready to return to normal operation, restart your iMac again (this time, without holding down any keys).
Table 20-1 provides the lowdown on start-up keys, which are available only with Intel iMacs. (iMacs with Apple processors use the macOS Startup Options screen instead, as described in the previous section.) Hold down the indicated key either when you push the Power button or immediately after the screen goes blank during a restart. (As I just mentioned, the Shift key shortcut to Safe mode for Intel iMacs is the exception; you should press it and hold it down after you hear the start-up tone.)
Some of the keys and combinations in Table 20-1 might never be necessary for your machine, but an Apple technician might instruct you to use them.
TABLE 20-1 Intel iMac Start-Up Keys and Their Tricks
Key | Effect on Your Intel 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 any bootable operating system on your iMac |
Shift | Boots in Safe mode |
T | Starts your iMac in Target Disk mode (using your Thunderbolt port) |
⌘ +V | Shows macOS Console messages |
⌘ +R | Boots from the macOS Recovery HD volume |
⌘ +S | Starts your iMac in Single User mode |
⌘ +Option+P+R | Resets Parameter RAM (PRAM) |
The macOS Disk Utility is a handy tool for troubleshooting and repairing your iMac’s drive — you can use it to check the format and health of both drives and volumes (and automatically correct any problems). You can find Disk Utility in the Utilities folder in Launchpad.
Fire up Disk Utility to open the rather powerful-looking window shown in Figure 20-2.
In the left column of the Disk Utility window, you can now see:
The volumes (the data stored on the drives).
You can always tell a volume, because it’s indented below the Container entry. (If you don’t see physical drives and containers as well as volumes, press ⌘ +2 to show all devices.)
USB or Thunderbolt external drives.
Figure 20-2 shows that I have one internal drive (the Apple SSD entry) and one USB flash drive (the PNY USB 2.0 entry). The internal drive has one volume (Colossus), and the external USB flash drive has one volume (Guardian).
Disk Utility can check the format and health of both drives and volumes, and you can correct any problems it finds by clicking the First Aid button.
You may not be able to immediately repair problems on your boot drive or boot volume. This limitation actually makes sense, because you’re actually using that drive and volume right now.
If First Aid finds a problem on your boot drive but reports that it can’t fix that error, boot your iMac from the macOS Recovery HD volume using one of these methods:
Then run Disk Utility from the window that appears. Because you’ve booted your iMac from the Recovery HD volume, you can repair those problems with your start-up drive. (You should be able to select your boot hard drive or volume and click the First Aid button.)
You can’t repair CDs and DVDs. CDs and DVDs are read-only media and thus can’t be repaired (at least by Disk Utility).
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.
To check and repair problems using First Aid, follow these steps:
Click Done to exit First Aid.
If changes were made (or if you had to boot from the macOS Recovery HD volume), Disk Utility may prompt you to reboot after repairs have been made.
Figure 20-3 illustrates the details you see if you click Show Details to expand the display. Although some of the messages might include cryptic Linux details, you can still tell from the figure that the operation is successful (and you get that snazzy green check mark). All is well!
As hip-hop artists say, “All right, kick it.” And that’s just what my iMac Troubleshooting Tree is here for. If rebooting your aluminum supercomputer didn’t solve the problem, follow these steps in order until you either find the solution or run out of steps (more on that in the next section).
The first step is a simple one that many novice iMac owners forget. Simply retrace your steps and consider what changes you made to your system recently. 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 next step is to run Disk Utility and use First Aid. The earlier section “Disk repair made easy” shows how to complete this task on your Monterey boot drive.
Cables can work themselves loose, and sometimes they fail. Check all the 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 in your cables or even Fluffy’s teeth marks.)
Check the contents of the Trash to see whether you recently deleted files or folders by accident. Click the Trash icon on the Dock to display the contents. If you deleted something by mistake, right-click the item in the Trash and choose Put Back from the contextual menu.
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 the norm, don’t forget an obvious problem: Your iMac can’t reach the Internet if your ISP is down or your network is no longer working!
When you’re at home, a quick visual check of your DSL or cable modem usually indicates whether a connection problem exists between your modem and your ISP. My modem has a set of informative activity lights that I always glance at first. If your iMac is connected to the Internet through a larger home or office network, however, and you can’t check the modem visually, you can check your Internet connection by launching Safari and connecting to www.apple.com
.
If you can’t reach your network at all, the problem lies in your network hardware or configuration. (In an office environment, your network system administrator will be happy to help you at this point, especially if you’re blood relatives.)
If you’ve made it to this point, it’s time to run a full virus scan. Make sure that your antivirus application has the latest updated data files. My antivirus application of choice is Avast Security for Mac from Avast Software (www.avast.com
). It’s both excellent and free!
Monterey might encounter problems with applications you’ve marked as login items in System Preferences. Your account’s login items are applications that run automatically every time you log in to your iMac. If one of these login items is to blame for your problems, your iMac will encounter some type of trouble every time you log in. (This is usually the case when you receive an application error message each time you start the computer.)
To check the boot process, it’s time to use that fancy Safe Boot mode I discussed earlier in the chapter. Follow the instructions for starting in Safe mode. Login items are disabled when you’re running in Safe mode, so if your computer starts up without any errors, you know that one or more login items are probably to blame.
If your computer starts without problems in Safe mode, the next step is to check your login items. Restart your iMac and then follow this procedure for each item in the login list:
Select the first item from the list and remove it.
You can delete the selected item by clicking the Delete button, which bears a minus sign. (If a recurring error message mentions a specific application that appears in the Login Items list, that’s your likely culprit, so start by deleting that item.)
If your iMac is still misbehaving, repeat Steps 2 and 3, and disable a new login item.
When your Mac starts up normally, you have discovered the perpetrator.
Delete that application and reinstall it.
Don’t forget to add back each of the working login items to the Login Items list using the Add button (which carries a plus sign)!
The next step is to turn off your screen saver. This remedy 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 are running a screen saver other than one from Apple, and your computer never wakes up from Sleep mode or hangs while displaying the screen saver, you’ve found your prime suspect.
Reboot your iMac (if necessary), open System Preferences, click Desktop & Screen Saver, and click the Screen Saver button. Then do one of the following:
Ouch. You’ve reached the final step, and you still haven’t uncovered the culprit. At this point, you’ve narrowed the possibilities to a serious problem, such as bad hardware or corrupted files in your Monterey System folder. Fortunately, macOS includes the System Information utility, which displays real-time information on the hardware in your system. To start System Information, follow these steps:
Don’t worry, friendly reader. Just because you’ve reached the end of my spiffy iMac Troubleshooting Tree doesn’t mean you’re out of luck. In the following sections, I discuss the online help available in macOS and on the Apple website, as well as local help in your own town.
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 the Apple website Support page (www.apple.com/support
); then click the Apple Authorized Service Providers link at the bottom of the page.
Always call your Apple Authorized Service Provider before you lug your iMac’s svelte frame all the way to the shop. Make sure you know your iMac’s serial number (which you can display in System Information) and which version of macOS you’re using.
Although most iMac owners tend to blow off the Help Center when the troubleshooting gets tough, that’s never the best course of action. Always take a few moments to search the contents of the Help Center by choosing Finder ⇒ Help to see whether any mention is made of the problem you’ve encountered.
If you haven’t visited the Apple iMac Support site yet, run, don’t walk, to www.apple.com/support/imac
. There, you find: