Drive storage and free space
Find your drive icon on your desktop (should be in
top-right corner or in side bar of a Finder window), select it with one
click, then choose "Get Info" from the Finder's File Menu.
The resulting window shows drive capacity, space
available and used space. If available space is
getting down to 10-15% of drive capacity, your drive is full; less than 10% means trouble ahead if not rectified soon.
About This Mac (Apple
Properly identify your machine by collecting its system
specs and details.
Select "About This Mac" under the Apple Menu in top-left
corner of screen. Here
you'll find your OS version number, details regarding your machine's
processor(s), installed RAM information, and the name of your startup disk. Clicking on version number
will cycle thru build ID, serial number, and back to OS version.
Much more complete and detailed specs may be found in the
System Profile by clicking "More Info" or "System Report" button within
"About..." window. Here
you'll find listed detailed specs of all internal components.
Illustrated here is System Profile's Memory pane, selected
in left column, showing
specifications for each installed memory module in each available slot.
Equally detailed and specific information is also available for every
drive, card, bus, port, and device from list on left side of Profile
If you use a notebook computer, you'll also
find battery condition and charging status located under "Power"
All Macs have their serial numbers recorded in "Hardware"
at the top of the System Profile window and in the initial "About This
Mac" window. Serial number may
found on back of MacBooks in wee-tiny print (and on a label inside
battery bay of way-old laptops with removable batteries). iMacs have
serial number and machine specs on underside of stand, towers have a
label under side door or on back panel. The serial number may be
used to ascertain warranty status and further identify machine specs.
For some inexplicable reason, Mac
model numbers are seldom used to identify individual models, even tho
machine has one. Macs are best identified by the specs on their labels,
in System Profile, or by machine's serial number. Other identifiers include order number (ending in LL/A),
two digits separated by a comma within System Profile's Hardware pane,
CPU speed and type, and by machine's date.
with an overall examination, take nothing for granted
If your iMac, Mini or tower is doing absolutely nothing - no
chime on startup, no fan, no sign of life at all - odds are the power
supply has failed. Laptops that aren't getting power will run on
battery until drained, then - nothing. Test and
power from outlets and check connections. bypass any surge suppressors
or power supplies (UPS), and try a different
If power isn't the problem, try going thru the
inspection process below as though you're seeing the machine for the
first time. Some steps may seem unnecessary, but try 'em
anyway, just in case. Be methodical.
Power down if necessary
Shutdown, then disconnect power to machine and unplug all
peripherals. Two reasons for this: First, it eliminates any possibility
of damage that might be caused by disconnecting/reconnecting powered
devices. Second, removing power from computer and all components for a
minute or two (including printer, modem, router, and all)
will cause some devices to reset when powered on again, thus
eliminating a few possibilities right off the bat.
While things are shut off and unplugged, take a good look at cables,
and ports. Are contacts clean and shiny, straight, intact and in good
shape? Any debris stuck in ports? Damaged cables
should be replaced, but damaged ports may be another matter; try a
different port if available. Carefully clean connectors as needed, blow
out ports and sockets, then reconnect
devices. Make sure plugs have a snug fit and cables aren't
being strained, twisted or bent.
If a new device has been added recently - including any
internal PCI cards - remove it and leave that device aside for now, to
be added back later.
(Hardware problems often manifest themselves during startup or
sleep/wake functions, causing
freezes, hangs or blank screens.)
power and startup
Connect and power-up peripherals first (printer, display, ethernet, USB
devices, etc,) and
allow each to go thru its startup routine - then startup your Mac and
see if problem remains or
If you've added a new device recently, try running without it for a
bit, then connect the new device and see if anything changes.
If problem never went away or startup to (desktop) is impossible, the
next steps may be unavailable and you might want to bring machine in.
Failure on startup
a note of what - if anything - appears on the screen and how long it
takes to get there. If machine sounds like it is starting up normally
but screen remains black, try to brighten the screen (usually the F2
key at top of keyboard). If it's still dark, shine a flashlight on the
screen and look for a ghost image of what should be visible on startup
- the login screen or desktop image. If you see anything, you've lost
If you see an icon of any sort, make a note of it. Various icons at
startup mean various things and are important indicators.
If you can shutdown normally, do so. If not, hold power button down for
6+ seconds until machine goes off. Next, try startup from Recovery:
Hold the Command + R keys down and momentarily press power button to
startup. Continue holding Command + R until you see the Apple logo,
then release keys and be patient; startup from Recovery takes a bit
longer than normal.
You should arrive at a screen where you pick a language and continue,
but eventually you should be presented with four options. The one we're
interested in is Disk Utility - choose Disk Utility.
You should then see your drive in left column, with first line showing
drive type and a second, indented line showing drive's name ("Macintosh
Select first line (drive type) and click Verify Disk. This checks drive
format, is usually pretty quick, and if successful it will say so. If
an error is found, it will show in red - make a note of it. If you have
the opportunity to repair, click Repair Disk ans see if repair is
successful. Continue with next step in either case.
NOTE: If you do not see your drive
in left column,
drive is not mounting and testing is done. Hold power button until
machine shuts off.
Next, select second line with drive's name and click Verify Disk again.
This time it will check the directory and will take a few minutes to do
so. As before, if a problem is found it will
appear in red - make a note of it. If you have the opportunity to
repair, click Repair Disk. If not, shutdown.
If you startup to a date/time error message, your desktop
computer's PRAM has been erased (common for notebooks) or clock battery
may be dead
(very rare, desktop machines only). Replacement batteries
are readily available for desktop Macs, but will require disassembly
(Notebooks have no PRAM battery, relying
on main battery to maintain settings.)
System Preferences and check settings in relevant
control panels and panes, and set date/time if necessary. Check Startup
Disk and select your drive if it isn't highlighted already. Look in
and Groups >
Login Items and see if there is something
launching on startup that might be the culprit. NOTE: Now is not the
time to change anything other than those settings that may be related
to the specific problem at hand; you're likely to see
login items installed by your OS (iTunes Helper, for example) that
remain. Third-party (non-Apple) items are always suspect and may be
to isolate the problem
Record any error messages that appear. Is the problem repeatable? Did a
action or event precede the problem? Does it seem to be related to a
particular application? If so, check the program's preference settings.
If problem appears to be related to an external device, make
sure any necessary
driver is current by checking version numbers and system
requirements. (Drivers on CDs included with most devices may be
unnecessary for use with Macintosh, or they may outdated
at time of purchase.) If you've done an OS upgrade, you may need to
download/update your printer driver, but drivers in general are seldom
a problem on Macs.
Before you call for
Regardless of where you might turn for assistance, you'll
save yourself time and trouble by having the following information
- Machine type (notebook, iMac, Mini or
tower), processor type and GHz speed, OS version
number, installed RAM and machine's serial number. Hard drive capacity
and available (free)
space might be helpful, too.
- Recent changes or events related to
issue, and specs for any peripheral device that might be
- A record of error messages, symptoms
encountered, and steps taken.
The amount of relevant information you have on hand when you
call tech support will determine a lot of your success in receiving
help. From a tech's point of view, it's much easier to have a coherent
conversation when both parties know what equipment is in use, under
which Operating System, and exactly what errors or symptoms are
NOTE: Using Google
to search for "customer support" will likely produce a top hit with a
toll-free number leading to offshore scammers. Carefully read the actual web address before clicking
any link, and go to vendor's genuine web site to obtain a _real_
If your Mac is under warranty, you may be entitled to free tech support
- check your warranty info (also available by serial number from
Apple's support page found under our Apple links). Most
hardware/software vendors charge for support by incident. We don't
provide free tech support, either. In fact,
it's rare to diagnose a problem over the phone, let alone solve it, so
we respectfully request you bring your machine to the shop for a proper
diagnostic evaluation. See our Service Policies and Ops page for
First, be patient; the beachball cursor is there to indicate
machine is busy. But, if it seems stuck for a minute or more, there's a
Quit..." command under the Apple (logo) menu that should get you out of
it. If that's not an option, you might have to force shutdown by
pressing/holding power button for 6+ seconds which will end a hang and
shutdown machine. Try startup and ops to see if problem was solved -
but don't be surprised if it happens again. If you want to
prevent beachballs in the future, or you find it's happening far too
often and for too long, then something needs to be corrected.
And the cause is...?
causes of slow ops - from minor to major - include:
- Using 'List View' with file size
displayed. Your OS will waste valuable CPU cycles as it calculates the
size of each file in folders you open. Use Column View instead (Finder
> View menu) or, if you
prefer List View, uncheck "Size" under View Options.
- A cluttered desktop littered with
over 2GB of folders, files, pics, music or video. Apps and huge
downloads on desktop can slow things down, too. File things where they
belong - within the
drive - and clean up that desktop. Empty the trash.
- Running too many apps at once.
Closing windows does not quit an application; when you're done with an
app, choose "Quit" from the app's menu or press Command+Q on the
- Unnecessary anti-virus and bogus
apps. Anti-virus apps insert themselves into practically every process,
and will slow things down with little or no benefit. Many legitimate AV
programs come with an uninstaller attached - use
"Slow" is a pretty vague complaint, and it helps to know if
related to a particular program - web browsers for example. Browsers
collect a lot of so-called "cruft" these days, a term encompassing
cookies, history, location info, icons, autofill and other web data. A
good habit to get into
these days is to clear cruft when quitting your web browser (Safari,
Firefox, etc.). If slow operation
is system-wide and not limited to a particular app, a little more
investigation is required, but we can usually get it sorted out if you
bring your machine to the shop.
complex causes: Internet downloads
and trouble-shooting apps can do more harm than good when installed,
and some are actually malicious. Many will slow ops to a crawl.
Purloined programs downloaded from offshore sources (torrent or
"file-sharing" sites) are always suspect
and frequently cause trouble - which is to be expected, since you're
dealing with thieves. Garbage may come onboard pretending to be Flash
Player, a "viewer," update, search assistant, cleanup utility or virus
scanner. One notorious example is MacKeeper, an
insidious scam that can be difficult
to remove. If you were unfortunate enough to install any
version of MacKeeper (paid or free demo), it will have to be removed
MacKeeper's "uninstaller" doesn't, and trashing MacKeeper won't remove
There are countless other browser extensions, bogus utility apps,
adware and malware on the internet hoping to get into your Mac; see
Security and Protection page for info on how to avoid junk and protect
In ballpark numbers, 2GB RAM will be consumed by your OS
alone. If you only have 2GB of installed RAM, everything will be slow
as System is forced to compensate. RAM is working space, and if the OS
it all, there won't be any left for other apps to use. Freezes/hangs
may result from running out of
memory or having too many apps running simultaneously. (Polite apps
warn you before they run out of memory, but don't count on it.)
of RAM required depends on what you use your computer for, and some
apps require much more RAM than others. Quit apps you're not using. A
simple shutdown and restart might help, too, if your machine sleeps
when not in use and seldom gets shutdown.
Other possible causes related to
slow, unresponsive Macs include failing or full drives, corrupt
or missing System segments, wacky apps, optical drives
or peripherals gone wild, and a whole slew of other things. A damaged
input device can mimic a freeze, too. Bring it in if necessary and
we'll figure out
what's slowing things down.
mail down or is all internet offline?
Either way, you might find a solution below.
Mail.app has a "Connection Doctor" function that might offer a clue as
to what has gone wrong if you are suddenly
unable to send and/or receive email. Try it. But
before assuming your computer is to blame, eliminate a few other likely
POP/IMAP = incoming mail settings,
SMTP = outgoing mail settings.
If Mail keeps asking for your
password, and you
anything, the problem might be on the server end. Some ISPs post
network status on their web sites, but most avoid mentioning down time.
If server is down, you will probably receive an erroneous message that
your user name or password is incorrect until service is restored.
Write down your email settings if you haven't already (user name,
password, POP/IMAP settings, port numbers, SSL yes/no and all SMTP
settings). If you change anything, these will have to be changed back
to the working set.
cables and devices
reset modem and router: Unplug power to each device for a few seconds,
then plug them back in and watch lights as they restart. Those lights
indicate signal and status, so if they all eventually light up
correctly they have reset and should be operational. A modem failure
stops all internet ops, not just mail. A failed router can be bypassed
by connecting computer directly to the modem with an ethernet cable,
then testing mail/internet.
Service providers also make periodic changes that might mess things up,
like the switch from POP to IMAP protocols, a new web mail program,
spam filter or security feature. If you've been ignoring messages from
your ISP regarding a pending change, now might be a good time to dig
one out of the trash and read it.
System Preferences > Network, and Mail.app prefs
A helpful Apple Mail.app support page may be found here: Mail.
It's important to make the distinction between ISPs and ESPs:
Internet Service Providers (ISPs) = Comcast, ATT, Cox, Hughes,
Wildblue, etcetera; these are cable, phone, satellite and microwave
Email Service Providers (ESPs) = Yahoo, Google, Hotmail, et al.
If you can't get online at all, it might be your ISP. If you can't get
mail, it might be either. Try web mail: Launch a browser (Safari), go
to ESP's server and login to your mail. That might narrow things down.
If you're on a wireless network (AirPort/WiFi), your AP menu and/or
Network pane in System Preferences should show name and status of your
selected network. If it shows as connected, your Mac and router are
communicating and the
problem is somewhere between router, modem and ISP.
If you use a laptop Mac, take it out on the town and try connecting to
network at a restaurant or friend's house. If it works on another
network but not at home, problem is not on your computer.
Modems sometimes fail, as do
routers, and most have lights indicating status. A damaged modem may
report any number of odd (sometimes misleading) errors, it may
endlessly try to connect or disconnect, its power supply may have
failed, or your network prefs pane may insist that there is no device
If none of this works, then either your ISP
is temporarily offline - there might be a phone number on your bill to
get a status report - or something more serious has changed that
requires further evaluation.
sure all connections are intact and power is on.
Sometimes it helps to power-up printers and peripherals
_before_ starting up your computer. Check printer's ink tanks or
cartridge. Look for any physical damage to the printer/scanner and its
ports. Make sure everything is properly connected. Unplug/replug cables.
Check settings and
Consult your printer/scanner manual
and try running printer's
self-test to see if the printer itself is malfunctioning. This may be
done with computer unplugged from printer. (Don't think scanners have a
Printers and Scanners. Make sure your printer
and/or scanner appears there and is selected. If not, its driver has
gone missing or was never installed. Go online
to manufacturer's web
site, find the support page, and look for the driver appropriate to
your printer or scanner model and your OS version. Download and install.
is producing distorted output (too small, too
large, sideways, missing fonts or styles), check and adjust Page Layout
or Page Setup options in the app's File menu.
appears as a page of gibberish, or machine spews out blank pages along
with the desired job, try printing
something from a different application. Launch TextEdit,
type something, and see if that prints properly. If so, the problem is
app-specific and Print options need to be adjusted.
driver and source
you've recently upgraded your OS, you may need to download and install
a new driver. (Same may be true of scanners.) Go online to manufacturer's web site, find their support page, and look
for the driver appropriate to your printer/scanner model and your OS
If you are trying to print a page
web site, know that web pages are not necessarily designed for printing
and output might be spread over multiple pages or distorted in ways
you wouldn't expect. There
are workarounds for this - but don't blame your printer. Try printing a
screen shot of the page.
ink tanks or cartridge
We've seen aftermarket ink tank "refills" leak and damage
printer's interior. If yours is an inkjet printer using third-party
cartridges, you might want to remove the tanks and inspect these where
they connect to printer.
It may be that your printer is simply worn out. If it's very old and on
its last legs, don't waste any time trying to fix it - new printers are
pretty cheap these days - probably cheaper than trying to make repairs.
and fine-tune your System
Adjustments in System Preferences will frequently solve
minor "problems" and may present options you were unaware of. Some
commands show or
hide controls, others produce shortcuts to apps and folders, and some
turn various features on/off or change appearance of windows.
Clockwise from top: Disk Utility, Finder
Prefs, System Prefs, and Get Info window
Utility (in Applications -> Utilities folder) is the only
troubleshooting and maintenance app you need. Launch Disk Utility,
click the First Aid tab and click Verify Disk at the first hint of
trouble - or, just to make sure all is well.
Select drive identifier (in blue at top of left column in illustration
above) and click Verify Drive button to check drive's format; this will
Select the indented drive name below identifier ("nCity1TB" in
illustration) and click Verify Drive button
again to check drive's directory. This operation will take a few
minutes, so be patient and wait until process is finished; best to quit
all other apps and avoid interrupting Disk Utility.
If any format or directory problem
is present, Disk Utility will let you know and tell you how to fix it. If your DU version has a Repair Disk Permissions button,
click that, too. Again, be patience, as this can take 5 minutes or more
if it hasn't been done in awhile. (Newer OS versions have automated the
permissions repair process, so there is no button.)
Show items in Finder's sidebar
Finder's Preferences (under Finder menu) and you will see four tabs as
illustrated above: General, Labels, Sidebar and Advanced. General tab
allows you to show/hide drive icons on your desktop, among other
things. The Sidebar tab will show important folders in every Finder
window sidebar; these should all be checked (on) by default IMHO, but
they aren't, so have at it.
Experiment with settings under Labels and Advanced, too, if you like.
Remember where these settings are in case you want to change Finder
pref settings again later.
Your System Preferences control the appearance and operation
of your machine's Operating System across all apps. System Prefs are
available from the
Apple menu or from its icon in the Dock.
User accounts, date/time settings, desktop color/image and
options, Dock settings, network settings (email and internet), printer,
keyboard and mouse, startup disk and a host of other controls are
System Prefs. Each of these controls can be changed and customized to
suite each user; settings are specific to each user account.
While we're on the subject...
Many people think clicking a close button in a window's top-left corner
() is the same as
quitting the application. It isn't. It merely closes the window (in
most cases), leaving the application open, active and running. Why is
this important? Because quitting unused applications frees up precious
Instead of clicking the close box when finished with an application,
choose Quit from the File menu, or type Command+Q.
Any and all
files and icons located anywhere in the Finder have metadata attached
describing that file's kind, size, location, dates created and last
modified, all sorts of helpful information and options. Handy when
trying to identify a file or sorting thru duplicates to see which is
newer or bigger. Get Info can answer most questions you may have about
a mystery file, including what apps will open it and which app it was
Disk Utility periodically
Applications -> Utilities folder is the Disk Utility application.
Running Disk Utility to verify your hard drive and repair permissions
can fix many minor errors before they become bigger issues.
PRAM Battery (aka "backup" or "clock" battery)
desktop Mac is over 10-years-old, its internal battery may be getting
weak. Symptoms on an iMac, Mini or tower include date/time error on
settings that may revert to defaults, and possible startup issues
rare). Very old Mac desktops used a 3.6v, half-AA-size lithium
battery with a life of 5 to 7 years, but all Macs with Intel CPUs have
a 3v CR2032 button battery that seems to last forever.
battery is easy for tower machines (Mac Pros), just make sure you pay
attention to polarity. MacMinis are a bit more involved, requires some
careful disassembly, and may be beyond a typical do-it-yourself job.
iMacs require major disassembly, expertise and special tools to access
the battery. The newer the machine, the more difficult service is.
However, the need to replace a PRAM battery is all but non-existent and
failures are very, very rare.
Notebook Macs don't have PRAM batteries as such; they rely on machine's
main battery to maintain settings (incl. date/time). Older laptops had
a capacitor instead of a PRAM battery (so that main battery can be
removed and replaced without losing settings), but new MacBooks don't
even have capacitors since main battery is difficult or impossible to
remove. Newer Retina-display and later MacBooks all have batteries
secured by adhesive. Entire top case, including keyboard, trackpad, and
battery is replaced as a unit.
Fan noise and/or excessive heat
laptop, all computers have fans in them these days to help cool
processors typically running at 140-150ºF. They all collect
dust over time.
shows where fan sits in a MacBook Pro and the dust it left behind.
Fan's exhaust vent is almost completely blocked with a
buildup of lint. Those little fins carry heat from machine's heatsink
to the fan, but they also catch fuzz from blankets, pets and
clothing that pass by. Whenever any machine gets serviced here at the
shop - desktop, tower or laptop
- we thoroughly clean fans, vents and interior because they all get
dusty over time. A good cleaning can add years to a machine's life.
In this case, the fan itself began to make noise and had to be
replaced. They sometimes get so clogged and dirty a fan may stop
All Macs have sensors within them to protect machine from overheating.
You may get a warning - or not - but machine will put itself to sleep
if it senses an overtemp condition, and/or shut itself off.
In normal operation, fans go on immediately at startup and ramp-up as
during normal use. They're usually so quiet you won't hear them, but
when they go full-tilt they can sound like a drone. If your Mac is
making noise, getting abnormally hot or fans are
running at high-speed all the time, it may be due for a cleaning.
Clear out browser cruft
versions of Safari had
a simple and convenient menu item that could empty Safari's cache
(right), or clear out everything all at once - the Reset Safari
command. Reset clears cookies, history, icons, auto-fill text, and all
the other junk (except bookmarks), setting Safari
back to pristine condition. Sadly, this command has been removed from
later versions of Safari. You now have to wade thru individual panes in
Safari Prefs to get rid of cookies, history, extensions and junk that
collects - collectively known as cruft. Clean out the cruft
periodically to keep Safari running smoothly.
other browsers also allow you to clear cache, cookies, extensions and
junk. These commands are
typically found somewhere in browser preferences or under Tools menu.
out old emails
mail apps so stuffed with old email - including unemptied trash and
spam - that messages number in the tens of thousands. (Current record
is almost 80,000.) Nobody has time
to sort thru all that. Clear out that inbox, delete all that spam, and empty the
trash. Try to empty your inbox when you retrieve
email by dealing with
incoming messages as they arrive. Mail Preferences has settings that
will automatically empty trash, spam and sent messages that are older
than a day, a week or a month, as you prefer. Or, you can manually
delete messages. Take the time to clean up and organize your email as
you see fit - it will streamline use and make things easier to find.
Archive old email
wish to keep
like, you can collect and export old emails from Mail to a TextEdit
rich text file, which includes all photos, graphics and live links.
First, select the messages you wish to save; the idea is to get them
all into a single group, so you might want to create a Mail folder to contain
them, then drag messages into that folder.
Arrange those messages by date, by name, subject
or whatever order you want to keep
them in; once exported, they will be end-to-end in one long file that
can't be rearranged later.
Select all messages to archive by using Select All in Edit menu, typing Command+A, or by
clicking the first one, scrolling down to the last one, then
Shift-clicking the last message.
With messages selected, choose "Save As..." in Mail's File menu.
From the resulting dialog box (above) give the file a name, select a
destination, and be sure to save in Rich Text Format, check the
"Include Attachments" box to preserve images, links
and attachments - all inline, with your messages - then click Save.
Five easy reasons to clean up those files
- Your primary hard drive - or boot
volume, if you prefer - requires a minimum 10-15% free space to run
efficiently. Deleting unused/unwanted files frees up valuable space. A
crowded, near-full hard
drive can be sluggish, and a full drive may eventually refuse to
- Searching thru organized files is
easy. When you save a file, pay close attention to where it is going,
and be sure to send it into the proper folder where it belongs.
Whatever scheme you use to sort and organize things is fine, as long as
it works for you. The Operating System creates a Home Folder for each
user, along with root-level folders for Applications, Documents, Music,
Pictures, Movies and the like - a good place to start.
- A neat, well-organized drive makes
for a neat, well-organized backup. Get all that junk off your desktop
or you may be seeing double when you mount your backup drive.
Empty trash (including email and browser cruft), and run Disk Utility's
First Aid now and then.
- Have a backup plan in place (see
Backup Schemes page).
- A nicely organized drive lends itself
well to customization. A nice desktop photo and screen saver, custom
window colors and fonts..... Since you'll be creating special folders
to hold special files, why not create custom folder icons while you're
at it? Google
"custom OSX icons" for ideas and custom icons if you like.
- If a drive fails - Heaven forbid - a
tech will have a much better chance of recovering your data if files
are well organized and properly stored. If recovery options
disintegrate to select/target files - photos, for example - there won't
be time to search drive for loose pics, but there might be a shot at
recovering the pictures folder in its known location.
Startup issues are best handled by exploring easy solutions before moving on to more
complicated ones. Start with status of the boot volume. If it's a
notebook, has it been dropped or damaged? Will it boot from its
Recovery partition? If so, does the main volume mount?
Simple as it may sound, failure on startup arrives in a
variety of ways with a variety of symptoms (and clues). Try to answer
- Did you hear the normal startup
sound? No sound (audio turned down or off)? A different sound, a long
tone or series of beeps?
- Does the power button light up? Does
it stay on, go off or flash once? Is it pulsing? Does any sound at
all come from the CPU (fans, drives spinning, other noises)?
- Does an icon appear onscreen? If so,
what does it look like? If machine hangs, what's on the screen? Is the
screen black, blue, or gray? What is the cursor doing? Do you get a message saying that you need to restart? Or
does it get stuck in a startup/shutdown loop all by itself?
- How far does startup get? Nowhere
screen), to the Apple logo, to a blank gray, white or blue screen, to
the desktop? What's on the desktop, what's in the menu bar? Anything
launching on startup/login?
- Is screen image distorted, striped,
checked all the usual suspects and machine still refuses to boot, try
starting up from your Recovery partition (hold Command+R on startup)
and see if you can run Disk Utility from Recovery. If so, try to make
Startup Disk in System Preferences
If your startup volume is not specified in System
Preferences, your Mac may take longer to startup as it searches all
connected volumes. Check your Startup Disk setting and make
sure the proper volume is selected.
Startup disk in System Preferences
special attention to the Operating System
Even if Disk Utility passes all tests, various hardware
tests pass, and all signs come up OK, that doesn't mean your Operating
is intact. A damaged OS can certainly prevent normal startup, but
it might not produce any errors during diagnostics.
If your drive contains critical data, unique photos, or important files
representing years of work, you do not want to risk losing it. Before
doing anything drastic
(like erasing/reformatting your drive, overwriting your OS with a new
one, or any number of other ways to make matters worse),
call for an appointment and bring it. If we can't recover your data, we
will know fairly quickly - and we can recommend a recovery service that
dreaded Kernel Panic (KP)
With instructions to restart in four languages, the old
Panic would appear with a gray curtain descending over the screen and a
black box with white text that didn't give you any choice. If it
appeared again after a restart, it usually meant something serious had
Newer OS versions don't even present the KP message; instead, machine
just automatically restarts itself. If restart solves the problem,
great. If not, machine will be stuck in a startup/shutdown loop until
someone holds down power button for 6+ seconds to stop it.
Before putting yourself (and your Mac) thru the trials
listed below, you might save yourself the trouble and risk of making
things worse by bringing the machine to our shop.
Having said that, presented below - for information purposes only - are
a few basic steps toward diagnosing possible causes of a Kernel Panic.
What follows is a brief test using the Recovery partition that should
have been installed to your drive with the Operating System (versions
10.7 on). If your OS is older than that, it's probably time to replace
First, shut off computer and
disconnect all attached devices. Then startup machine and see the KP
has gone away. Yes = suspect external device, no = internal problem.
Normal troubleshooting routines start by checking simple things first
in search of a quick fix, but troubleshooting Kernel Panics is a little
different. By eliminating connected hardware components, we are
eliminating them as possible causes. They can be reconnected, one at a
time, and tested individually if KP was solved without them.
Do not attempt to make any sort of repairs or startup from any software
than your current Operating System.
Newer versions might be okay, but anything older than your current OS
is certain to fail (if you're lucky) or cause further damage (if you're
These can be indicative of both hardware and software
problems, making them difficult to troubleshoot.
Possible causes range from
defective or failed memory (RAM) to damaged
ports, connectors and peripherals. Failing or corrupt drives, failed or
damaged video cards, everything from a damaged logic board to a corrupt
font. Older OS versions produced a gray screen with black dialog box as
If hardware is not the cause, other suspects include
corrupt or damaged Operating System, firmware issues, device
drivers, even corrupt fonts and incompatible apps. The list
goes on and on.....
while running, versus KP on startup
The timing of a KP's appearance can be a significant clue as
to its cause. If KPs appear during the course of operation, it might be
connected to use of a particular application, a specific OS component,
or a device driver. If so, uninstalling and/or reinstalling (or
updating) the suspect software might return your machine to normal. If
you're not sure about deleting things, don't. Just make a note of
file's name and location.
If a KP appears on startup - on each and every startup - the
problem is probably more serious. It might still be a software issue of
some nature, but more often than not it will turn out to be hardware
changes might suggest cause
With so many potential causes, it might be helpful to recall
events immediately preceding the appearance of a Kernel Panic. Recent
changes or hardware/software installs may have
been the cause; KPs might not appear until your next startup, so go
back to the last change that was made.
Apple Hardware Test
Try booting from Apple Hardware Test (AHT) by holding down
"D" key at startup, or by using Startup Manager; select AHT and
startup. With some OS versions, there is no AHT, so don't be surprised
if "D" key is ignored.
Run AHT's Quick Test if possible. If the Quick Test turns up nothing,
Extended Test. If no error is produced, you might try letting it loop a
few times. AHT may uncover hardware issues, but it does not test
If all tests pass
without error, and all hardware is properly identified, that - sadly -
does not mean everything is A-OK. We've had machines refuse to boot
from anything except AHT - and
pass all AHT