Macintosh Troubleshooting
Frequently Asked Questions rev. 3/27/01
Created by Larry MacPhee and Stan Woo-Sam
General Help | Startup Trouble | Crashes, Freezes, Slowdowns | System Alerts/Errors | Memory Problems | Problems with Files | Problems with Disks | System-Wide Problems | Hardware Trouble | The Bleeding Edge | Mac Shopping

Note: In this guide, the rainbow apple refers to the Apple Menu in the top left corner of the screen. The black apple refers to the Apple key (also known as the Command key) on the keyboard.

General Help

Where to begin?

Apple has a nice introduction to the art of troubleshooting at It's not specific to Macs but rather goes through the thought process of figuring out a problem.

How can I get help in learning how to use the computer?

AppleGuide is a help program that you can find by looking under the Help menu (or the "?" in the upper right area of the screen in System 7). Lots of useful information about the Macintosh is stored here and it will actually show you how to do many things! Even the help balloons are sometimes useful in learning a new program.

Startup Trouble

What should I do if the computer crashes while starting up?

When your machine boots up, a number of icons march across the bottom of your screen from left to right. Computer crashes during startup are usually due to conflicts among these Extensions and Control Panels. You should restart the computer while holding down the shift key. This will disable all optional extensions and control panels. If the machine now boots up successfully, then it is likely that you were having an "INIT conflict". Then you can selectively turn them back on using Apple's free Extensions Manager (or the commercial Conflict Catcher or shareware utility Extension Overload) to try to uncover the conflict. If it's installed, Extension Manager's control panel can be automatically called up on startup by holding down the space bar during startup, or can be accessed through the Control Panels. Put a checkmark () next to all items you want to load on startup. Did you recently install some new piece of software? It could be the culprit, or it might have created a conflict with something that was previously installed and working fine. Try removing anything installed just before the problem arose (hardware and/or software) and see if the problem disappears.

How do I specify the boot-up device?

Under ordinary circumstances, your Mac will try to boot from devices in this order: 1) internal floppy (if it has one), 2) hard disk, 3) CD-ROM drive, 4) and finally any bootable external device. Inserting a bootable floppy (such as Apple's Disk Tools) during startup will cause the system to boot up from floppy instead of the hard disk. To force the computer to boot from the internal CD-ROM drive (such as the Apple system software CD), hold down the "C" key during startup. To bypass the internal hard drive and boot from an external device, hold down the , Option, Shift and Delete keys simultaneously. You can also set the preferred startup device with the "Startup Disk" control panel so that a particular device will be selected on restart. On recent Macs, you can force it to "net boot" by holding down the "N" key, but this will only work if you have a net boot server.

What do I do if my computer won't boot up? (Accompanied by blinking "?" or a blinking folder icon)

This generally means that your System Software is damaged. Boot up from the Disk Tools floppy disk or from your System Software CD. The CD's default installation is to do an "Easy Install" which puts new software on top of old and preserves your custom settings and third party extensions. If that doesn't work, choose the Clean Install option. This will install entirely new system software, leaving the old system in a deactivated "previous system folder". Be sure to move preference files, browser bookmarks, e-mail folder and any third party extensions from the old system folder. On recent models such as the iMac, you have the option of doing a System Restore, and you will be asked whether you want to wipe the hard drive and return things to the factory settings or to install over the damaged system files leaving your data in place.

Here's Apple's official word on Startup Issues:

Crashes, Freezes, Slowdowns

Why does the Mac crash?

Almost always it's a software problem. Computers usually "crash" or "freeze" because they received confusing instructions from the programs they are running. Many of these problems arise because of conflicts of interest between the various Extensions and Control Panels. Sometimes a program will have a line of code which instructs the computer to do something "illegal" or incomprehensible- this is when we refer to a program as having a "bug". Bugs often cannot be fixed until a new version of the program comes out, or sometimes a small bug fix or "patch". New software may crash because it expects too much from older, more primitive hardware. Old software may crash because it doesn't recognize more advanced hardware or chip designs. Many newer programs like Microsoft Word and Netscape are memory hogs and they may crash if you don't give them enough RAM. So there is no single reason for problems. The best thing you can do is to methodically try to define the problem so it can be isolated and dealt with.

How do I regain control if the computer crashes while I am working?

1) Try to quit from the "hung" program using a "force quit" (-option-escape), and then save your work in other open applications (if possible) and restart the computer. Some problems go away and never return after a restart.

2) If #1 won't work, restart the whole computer using a "soft-boot" (-control-reset). Reset is the triangular button at top right of the keyboard. It is also the Power On key on some models. (Note: This will only work on beige, pre-USB Macs. For the new, colorful Macs, jump to step 3).

3) If #2 won't work, press the "reset" button to reboot the computer. Unfortunately, location varies. On the latest model Macs with USB (the colorful ones), only the reset switch (a small button with a triangle on it) will restart the machine after a crash because the keyboard and mouse are disabled by the crash. On iMacs, the reset switch is on the right side. On towers, it's on the front face. On PowerBooks, it's on the back.

4) If #3 won't work, restart the computer using the power switch or by pulling the plug. That always works (except on a laptop; in the case of extreme crashes on a laptop, you might need to remove the battery. See your owner's manual).

What should I do if a program or device that used to work reliably now crashes the machine repeatedly?

First ask yourself this question: "Has anything (software or hardware) been changed (added, removed, updated) on this system?" If this change coincided with the instability, try putting things back the way they were before the problem started. Try to isolate the problem. Take note of what the computer was doing when it crashed (Were you printing, starting up a program?). Can you re-create the conditions before the crash and make it crash again? Sometimes throwing away the program's preference file (buried in the Preferences folder of the System Folder) fixes the problem. Alternatively, you might want to delete (uninstall if you can) and then reinstall the application from the original diskettes or CD or do a clean install of the system software if nothing else works.

Could my computer have a virus?

Usually not, but there are a number of Anti-virus packages that can put your mind at ease. The most troublesome Mac viruses these days are the Word and Excel Macro viruses. There are hundreds of strains, and they can jump from PC to Mac without difficulty. Typical virus symptoms include abnormal behavior, sluggish performance and frequent crashes in previously stable, well-behaved programs.

System Alerts, Errors

What does it mean if there is a blinking icon in the top right corner of my screen?

The computer is trying to get your attention! Click and hold on the icon for the Application menu in the top right corner of the screen. When the menu appears, select the application with the diamond () next to its name, and a message from the computer should appear. Read the message and take appropriate actions.

I just got a System Error of Type XX! What does it mean?

Sometimes the number of an error is informative, and sometimes it is merely the symptom of some other problem. There are several reference programs that let you look up System Errors. Try Black and Bleu, Apple Error Codes-98 or Bombs Away.

There's an empty white box on my screen. How do I make it go away?

You've accidentally hit the programmer's switch. Push the "g" key on the keyboard and then the Return key. Apple explains:

Memory (RAM) Problems

What should I do if a program gives me a message that it is "out of memory"?

1) To see how much RAM you have, and how it is being allocated, go to the Finder using the Application menu (top right corner of screen) and then look under the menu for "About this Computer". New computers are generally sold with barely enough memory (RAM). Modern software hogs a lot of memory; the system software alone can consume 20 or more MB!). I'd recommend 64 minimum,128 Megabytes for a bit of breathing room, and 256 or more for the "Power User".

2) Quit from any programs you are not currently using to free up more space (Check the application menu to see what programs are active by clicking and holding down on the computer icon in the top right corner of the screen). Note: A program may be running (and taking up memory) even if it has no open windows. Try File/New to open a window, or File/Quit to exit the program. Windows users often think they have quit a Mac program just by closing the window. On Macs, the program stays open even when all windows are closed.

3) If you have memory to spare, you can try allocating more memory to the problematic program. First, save your work and quit the program. (This setting cannot be changed while the application is running.) Find the program icon and click on it once with your mouse. Now hit the keyboard buttons "-i" (the letter i for info), or choose File/Get Info. A window will open telling you how much memory the program has been told to use. (In recent OS versions, the memory settings are hidden in a pull-down menu in the Get Info window). You can increase this allocation by typing in larger numbers in the "preferred" box.

4) If you suspect bad RAM or if your installed RAM isn't being recognized by the system, there's a secret section of the memory control panel called Startup Memory Tests. You can access it by holding down -Option while opening the control panel. By default it is on. Try turning it off. If that doesn't work, you may need to remove the bad RAM chip.

What should I do if the computer doesn't have enough RAM to spare?

Short Term - If you have no memory to spare (and no time or money), you can turn on "Virtual Memory". Under the menu, choose Control Panels/Memory. This allows you to raise the amount of memory your computer has by using free space on the hard drive as additional RAM. You must restart the computer for these changes to take effect. The cost to this strategy is reduced performance, since reading and writing to the hard drive is slower than reading and writing to real RAM. Commercial programs such as RAM Doubler may help you to stretch your memory further, but they aren't much good unless you have a fair bit to start with (minimum of 32 Mb), and they don't work well if you need to use one very large program (as opposed to several smaller ones at the same time).

Long Term - You should buy more memory. It is pretty cheap right now. However, the price of memory fluctuates daily so watch the prices and shop around before you buy. Check the RAMwatch page for the latest prices. How do you know what kind of memory is right for your machine? Download the memory reference program, Guru, for free or use the online Memory Wizard. It is an up-to-date resource that tells you exactly what you need. Good places to buy cheap Mac memory chips are MemoryToGo and RAMJet.

Problems with Files

What do I do if the icons have lost their pictures?

There is an invisible file on the Mac called the "desktop database" which keeps track of where files are stored and what their icons look like. Apple recommends that you rebuild the desktop about once a month in order to keep this file up to date. On startup, hold down the and option keys simultaneously until a dialog box appears. It will ask if you want to "rebuild the desktop". Click OK, and wait a few minutes while it rebuilds. This will usually fix your generic icons. If it doesn't work, download the free TechTool utility and use it to delete the desktop database forcing a new one to be created.

For Apple's official word on rebuilding the desktop, look at

What should I do if my file (document) or application program is damaged?

Easy. Just restore it from the latest backup or from the application's Install CD. What? You don't have a backup? Well, now you've learned a valueable lesson. Don't let this happen again! Disk utilities repair the directory structure of disks but not damaged files themselves. It is very difficult to recover data from a corrupted file; usually it must be deleted and recreated. You can try using ResEdit or Norton's Disk Editor to recover data, but the odds usually aren't good.

What should I do if I've accidentally deleted an important file, and I don't have a backup?

When you delete a file from the computer, you aren't really erasing it. You are just telling the computer that it's ok to overwrite the space that the file took up. Therefore a deleted file may still be there, and can sometimes be recovered! When trying to un-delete, it is important to try to recover your data as soon as possible after deletion, since the chance that the file has been overwritten (and therefore permanently lost) increases with time. Norton Utilities is a good program for "unerasing" deleted files. Norton's unerase function works best if you use it to catalog your drive regularly with its "FileSaver" utility. Avoid installing any programs or saving any files to the drive until after you have attempted the recovery (boot up from your utility CD if the unerase program isn't already on the hard drive). Norton also has a "Wipe Info" function which can erase files so that they cannot be recovered with an Unerase utility. This is an effective way to destroy confidential documents.

Problems with Disks

How do I erase a floppy disk if the Special Menu's "Erase Disk..." option is gray?

Is it possible that the disk is locked? If you look on the back of the disk, there's a little tab in the top left corner. If the tab is down it's unlocked and can be erased. If the tab is up (and you can see through the hole) it's locked and can't be erased. Just eject the disk, flip the tab and try again.

What's going on? My USB floppy drive doesn't recognize some of my old disks.

If you are using an external USB floppy drive on a new floppy-less Mac, be aware that they only read and write high-density disks (and they don't even do that very well in my opinion). (You can tell a high-density disk by the "HD" symbol on the disk (front side next to the metal shutter). Really old Macs like the MacPlus could only read low density (400k) and double density (800k) disks. Most "beige" Macs that are still in use today can read the older disks as well as the newer high density disks. If you have vital data on an old disk, find somebody with a beige Mac that has a built-in floppy drive and transfer your data to a high-density disk that your new Mac can access.

How do I get a stuck disk (floppy, CD, ZIP) out of the drive?

On a Mac, disks are normally ejected automatically. If they get stuck, you can try to eject them manually. Although the Mac has no external manual eject button, there is a tiny hole, usually* on the lower right front of the drive. Straighten out a sturdy paperclip and push it into the hole to trigger the eject mechanism. Don't force it. It should come out fairly easily if it's going to come out at all. It is best to restart the machine after a manual eject because the computer doesn't know what's in the drive.

*On an external ZIP drive, the pinhole is in the back.

What should I do if my disk (floppy, zip or hard disk) is damaged?

In the case of a damaged disk, it's often the loss of the directory structure of the disk that causes the biggest problems. It's as though the library's card catalog has been stolen, thereby rendering all of the books useless because there's no way to find them. First run Apple's free Disk First Aid. Recent versions are quite good but also, importantly, it is very safe (occasionally a disk repair program can make things worse if it encounters serious problems!). Disk First Aid can also be used regularly for preventative maintenance to keep small problems from growing into big ones. A new and more powerful disk repair program is Disk Warrior. It fixes severe problems in an innovative way, by rebuilding the damaged disk directory piece by piece. Disk repair programs can often do a better job if they are installed before the problem arises. This is particularly true of Disk Warrior. Occasionally a combination of programs can fix a problem that was unfixable by one alone, so it's a good idea to have several tools available when (not if) disaster strikes. Norton Utilities and Tech Tool Pro are good fall-backs.

What if the disk repair program doesn't fix the disk?

If a floppy has given you trouble, reformat it. If reformatting encounters any problems, throw it away. It isn't worth trusting. If a hard disk fails repeatedly, do a low-level format and update the hard disk drivers with Apple's Drive Setup utility. If it's an external SCSI device, see below. If it continues to be unreliable, replace it.

System-Wide Problems

What should I do if the date and time are incorrect (1904 or 1956?) and the monitor is displaying in black and white?

Your computer needs a new internal battery. All* Macs from the SE to the G3 (except PowerBooks) take the same one. You can get one at Radio Shack or It's a 3.6 volt lithium long life battery. A dead battery can also prevent some models from starting up, so it's a good first thing to try if your computer "plays dead".

* OK, there were also a handful of short-lived Performa models and Mac clones with a weird battery.

What do I do if the computer is behaving very badly and I've tried everything above?

Zap the p-RAM by restarting the computer while holding down the , option, P and R keys simultaneously. Do this several times. This resets to factory settings a variety of preferences that are normally maintained by the battery. Unfortunately, this seldom helps. It may be time to call in the experts. Note that after you zap the p-RAM, the network setting reverts to AppleTalk and you will need to reset to Ethernet if you are on an ethernet network. For an even better zap, download the free TechTool utility.

The entire computer is acting can I tell if it's software or hardware?

Do a Clean Install of the System Software or a System Restore from the CD that came with your Mac. See above under Startup Trouble for more information. If you think the hard drive might be the problem, see above under Disk Trouble. If the machine is still flaky, begin to suspect a hardware problem.

Hardware Trouble

What if I suspect a hardware problem?

On any recent Mac, use the Apple System Profiler (under the menu) to see if the device/component is visible to the computer. If not, it might be dead. In addition to repairing disks, Tech Tool Pro does some hardware diagnostics. If you suspect a particular hardware component, first check the connections. Even internal components sometimes become unseated, particularly after a move. You could try removing the suspicious component (in the case of a RAM module or floppy drive, for example) and see if the problem disappears. Better yet, if you have spare parts (or additional machines of the same type), you can try exchanging pieces between a "good" and "bad" machine and see if the problem moves with the part. Do this one piece at a time or you won't know which one it was. Sometimes floppy and CD-ROM drives that don't read disks just need a good cleaning. Buy a cleaning kit and/or try blowing the dust out of a malfunctioning drive. Shine a flashlight inside of a malfunctioning floppy drive to look for loose objects. Sometimes floppy disks leave their shutters inside the drive. If you need to remove an object from inside the drive, unplug your computer and then try using tweezers. If that fails, you may need to disassemble the drive. Try a low level format on a malfunctioning hard drive before you give it up for dead. Monitors are almost never worth fixing, and they can hold an electrical charge (even while unplugged!) for a very long time (months?), so keep out! To run performance diagnostics on your Mac, download the free Gauge Pro tool from NewerTech.

What should I do if I'm having problems with an external SCSI device?

Use SCSIProbe to scan the SCSI bus and detect devices. Here are the basic rules of Mac SCSI: Any SCSI device that you wish to use with your Mac should be powered on before the computer starts up. When you connect/disconnect devices you should first shutdown and power off all SCSI devices. Every SCSI device must have a unique address (ID #) for each SCSI bus. Most beige Macintosh computers have one SCSI bus. ID numbers must be in the range 0 through 7 (the Macintosh is 7); the internal boot hard drive is set at the factory to ID 0 and the internal CD-ROM drive is set to ID 3. An Iomega Zip drive can only use ID 5 or 6. Termination must be correctly set. The end of the SCSI chain must be terminated. If you add external devices, you simply need to terminate the device physically furthest along the chain from the computer (Termination ON for last device, OFF for all others). Active termination is required for Fast and Ultra SCSI, and desirable for regular SCSI as well. It is important to use good quality cabling and not to exceed the limit of 6 meters (about 20 feet) for regular SCSI. Fast and Ultra require much shorter distances. Most SCSI devices need a software driver (often a control panel and/or extension) that is installed on the computer when the device is first configured. The driver provides instructions to the computer on how to access the device. It is important that the driver be compatible with the computer and version of Mac OS you have. The company that distributes or publishes the software can provide compatibility information.

The Bleeding Edge

What if I have a problem with a recently released Mac model or software program?

Sometimes it takes a while for the software to catch up with new hardware, and sometimes new software versions (especially any software version number ending in .0 (point oh)) are a little buggy. Try MacFixit or check the Apple Tech Info Library. It's also a good idea to read the Mac news pages on the web. They are often the first places to report problems. Check out MacInTouch, MacNN, MacCentral, MacWorld and MacSurfer. If you like gossip and rumors about the Mac, visit MacOSRumors or ThinkSecret.

How can I keep my software up to date?

If your computer has OS9 or newer and you have Internet access, use the Software Update control panel to automatically keep your System Software current. It's slow but, if you set it to update your machine overnight, it works while you sleep and it's done in the morning. If you have an older System than OS9, or if OS9's Software Update isn't working properly, you can also get updates directly from Apple's Software Downloads web page. Also, be sure to visit Version Tracker for the latest updates to all your Mac software. It's one of the best Mac resources out there.

Mac Shopper

There's no Mac stuff in the store! Where can I buy Mac software and hardware?

The lack of Mac stuff in retail computer stores contributes to the misconception that there's little software and hardware for the Mac. There's a ton of Mac stuff out there if you know where to look. For the bargain hunter, go to Deal-Mac. The best mail order and Internet places to shop for Mac stuff are the Apple Online Store, Outpost, MacWarehouse, MacZone, MacConnection, and ClubMac. Avoid MacMall. They are the only major Mac catalog/online sales place with a negative rating from the Better Business Bureau. (Note: If you buy anything from any one of these places, you'll be getting Mac catalogs for life!) If you want to see the stuff in person before you buy, try your local Sears, Circuit City, Fry's Electronics, MicroCenter, CompUSA or your university computer store or the Apple Retail Store near you. A word of warning though...the sales people in most retail stores don't know much about Macs, so take their advice with a grain of salt.

Where can I find Fun Stuff for my Mac?

OK, this is off topic but here are a few recommendations...Check out MacDesktops and the Icon Factory for starters! For games, go to Mac Gamers Ledge. For digital cameras, check out the Digital Camera Resource Page. Links from these sites should get you lots more. Finally, try hunting for Mac shareware. There's great stuff out there!