Hard Cider Index
by Ted Landau
The "?" Disk Icon or a Reappearing Happy Mac
Symptoms:
The ? disk icon remains on the screen indefinitely, or the
happy Mac icon appears, disappears, and reappears in an endless
loop.
Causes: The most common cause is that the Macintosh
cannot locate a valid startup disk. If so, the compter sits
and stares at you with the blinking question-mark (?) disk
icon, asking you to insert a startup disk and waiting until
you do so. For example, this would happen if you turned on
your Macintosh without a floppy disk inserted and with no
hard drive connected.
If the ? disk icon persists even when a supposed startup
disk is available, you have a more serious problem. Usually,
the problem is with the startup hard drive. Either the disk
is not connected properly (which can easily happen with an
external hard drive), the software on the disk is damaged,
or a hardware repair is needed.
A cycling happy-Mac icon indicates similar causes, especially
damaged software. Other possible causes include incorrect
SCSI connections or corrupted Parameter RAM.
What to do: Try each of the following items, in turn,
until one is successful in getting your Macintosh to start
up. Remember to turn off all the devices before disconnection
or reconnection any cables.
If your Startup Disk Is an External Hard Drive: Check
Connections
Make sure that the external drive is connected properly
to the Macintosh. Make sure the drive is on and plugged in
to a power outlet. Check that all cables are firmly connected.
Restart.
If Your Startup Disk Is an Internal Drive:
Disconnect Any External SCSI Devices and Restart
Disconnect the SCSI cable from the back of your Mac.
If this succeeds in getting your Mac to start up, you probably
have either a SCSI connection problem or a hardware problem
with one or more of your external SCSI devices.
Check Indicator Lights
Most hard drives have one or two indicator lights
on the front of the unit (the light is built into the front
panel of the Macintosh if it is an internal drive). If there
are two lights, one usually indicates that the drive is on,
while the other only goes on if the drive is being accessed
(reading or writing). If there is only one light, it is usually
an access light. In either case, the light should go on -
at least intermittently - at startup. If it does not, it means
that the drive is not functioning (assuming that the light
bulb itself is working okay!), and a likely hardware repair
looms ahead.
Restart the Macintosh
Restart Again with the Same Disk as the Startup Disk
Hopefully, the problem will disappear, in which case your
troubles may be over. If it returns later, however, you may
have an intermittent problem, such as stiction.
Restart with a Alternate Startup Disk If the previous
restart did not work, try restarting with a alternate disk,
preferably a floppy disk. If this succeeds, continue to the
next step.
By the way, if you are starting up from
a floppy disk, you can still change settings of some control
panels on your hard disk. For example, you could change the
Startup Disk setting from an external drive (if that is its
current setting) back to an internal drive for your next restart.
Check for System Folder Problems
If you can get the Macintosh to start up with an alternate
startup disk, check to see if the problem disk has mounted
and is now present as a secondary disk (that is, its icon
is shown below the startup disk icon on the Finder's desktop).
Most likely it will be there. If so, check for the following
problems (using the problem disk as the startup disk, restart
the Macintosh after each attempted solution to see if the
problem is solved).
Make Sure a System Folder Is on the Problem Disk Okay,
presumably you already know that a System Folder is there.
But just in case, check anyway. If there isn't one already
there, install a System Folder and start again.
Make Sure there Is Only One System Folder on the Disk
Multiple System Folders (or, more technically, more than one
copy of the System file and/or Finder) on your startup disk
are not likely to cause startup problems, especially if you
are using System 6.0.7 or later. Still, to be safe, it is
good practice to delete all but the intended startup System
Folder from your disk. If you are unsure whether additional
System Folders are present, you can use the Finder's Find
command to search for "Finder" or "System."
Bless the System Folder If Necessary Using the Icon
View in the Finder, check to see if the System Folder has
the mini-icon of a Macintosh on it; this is the indication
that you have a blessed System Folder. The Macintosh typically
does not accept a disk as a startup disk, even if it appears
to have a valid System Folder on it, unless the latter is
shown as a blessed System Folder.
Normally, all System Folders are blessed folders unless there
is more than one on the same volume, as described just below.
Occasionally, however, a problem may develop where an apparently
valid System Folder is not blessed. For example, the utility
System Picker unblesses otherwise valid System Folders. Similarly,
if you remove the Finder or System file from a blessed System
folder, it will become unblessed; replacing these files will
"rebless" the folder.
Also an unblessed System Folder may be a warning signal that
there is more than one System Folder on your disk. This is
because a disk can have only one blessed System Folder on
it, which is the one that the Macintosh actually uses when
it starts up from that disk.
If the System Folder isn't blessed, open the System Folder
to check if the essential files (System, Finder and possibly
an Update file) are really there. If they are, remove the
System file from the System Folder, then close the folder.
Now open it again, replace the System file, and close the
System Folder once more. This usually reblesses the System
Folder. You should now see the mini-icon of the Macintosh
on the folder.
Whether the mini-icon appears immediately or not, try restarting
with this disk as the startup disk. The disk will most likely
start up without further problems.
|
TECHNICALLY SPEAKING |
| BOOT BLOCK PROBLEMS
Corrupted or incorrect data in a disk's boot blocks
are the technical reason why an apparently valid System
Folder may appear as unblessed. Such a disk does not
start up properly.
In some cases, the procedure described here for blessing
the System folder fixes a boot block problem. Otherwise,
you may have to resort to special utilities (such as
Norton Utilities and MacTools)
that repair boot blocks. If there is a boot block problem,
these utilities find it, report the problem to you and
fix it. If they cannot fix the problem, your last resort
is to reformat the disk. |
Replace the System and Finder If the previous steps
have not worked, the System file, the Finder and/or the Update
file may be damaged. TechTool and TechTool pro are useful
for checking for damage to these files. Otherwise, to be safe,
just replace the files. You might also try replacing the Finder
Preferences file.
Check for Startup Partition Problems
If your startup disk is divided into partitions, only
one of those partitions can normally act as the startup disk.
If you place a System Folder on another partition and try
to select it as the startup disk (via the Startup Disk control
panel), it will not work. In some cases (depending on your
particular disk driver and especially if the only available
System Folder is on the partition that cannot act as the startup
disk), the result may be that you get the cycling happy Mac.
If this happens, follow the steps listed here.
Select a Different Startup Disk First, start up from
a floppy startup disk. Then, if needed, install a System Folder
on the partition that can act as a startup disk. Next, select
that disk (or any other valid startup volume) as the startup
disk from the Startup Disk control panel. (If you had used
System Picker originally, you may need to use it again to
select a new startup disk.) Restart.
Update Your Disk Driver Switching to a different disk
driver may eliminate this cycling happy-Mac problem altogether,
allowing you to start up from the previously problematic partition.
In general, however, you will keep these and other related
problems to a minimum by using the disk driver from the utility
that was used to format your disk and by using the same utility
for all of your mounted volumes.
An incorrect or out-of-date driver can prevent
startup even if the driver is on a secondary hard drive rather
than the startup drive itself! All mounted drives should have
correct drivers.
| PowerBook 150 alert: If you replace the hard
drive that comes with a PowerBook 150 with another IDE
hard drive, you will likely find that you cannot use this
drive as a startup disk. The reason is that the PowerBook
150 reads the disk driver from its ROM and will not start
up if there is another driver on the disk itself. To get
things to work, you must format the disk with the Internal
HD Format utility that came with the 150. Unfortunately,
if your new disk is already formatted, Internal HD Format
will refuse to work. So any new hard drive you purchase
must be completely unformatted, or you can use a utility
such as Norton Utilities to zero
out the boot blocks and partition map. Either solution
will allow the disk to be reformatted. |
Zap the PRAM
Parameter RAM (or PRAM) is a special type of memory
that is preserved by a battery inside the Macintosh even after
the computer is shut off. Some of the data stored in the PRAM
relate especially to SCSI connections. If the data stored
in PRAM become corrupted, they can prevent a hard disk from
mounting properly. Zapping the PRAM restores the data to their
default value and should solve this problem.
Battery Problems
There have been reports that if the battery installed
on the logic board of your Mac (the one that maintains the
PRAM setting etc.) goes dead, you may lose not only your PRAM
setting but the ability to start up you Mac at all. Fortunately,
replacing the battery fixes the problem so no major repair
is needed.
On some Macs, a dead battery may result
in a normal startup except that the monitor display remains
black. If this happens, try zapping your PRAM. If the video
comes back, you probably need to replace the battery.
Make Disk Repairs
If none of the preceding solutions worked, or if the
problem disk did not mount when starting up with the alternate
disk - or if you could not start up at all when using a alternate
disk - try the following steps.
"Repair" and Defragment the Disk If you
get the blinking question-mark icon as soon as you restart
after a system crash (or some other improper shutdown), you
may have something called the Disk Check bug. What is happening
is that the Macintosh's startup diagnostics are mistakenly
reporting a damaged disk, even though the disk is fine.
to fix this, use a repair utility, such as Disk Doctor (Norton
Utilties), to "repair" and mount the disk.;
This disk will now work normally.
to prevent this from happening in the future, defragment you
disk. Continue to defragment it on a regular basis.
To see if you are even susceptible to this
particular bug, run a freeware utility called Disk Bug Checker.
Supposedly, this problem has been fixed altogether in System
7.5 and subsequent revisions.
Last Resort If none of the previous solutions worked,
check for other disk damage, corrupted data, or a hardware
problem. For starters, try running Disk First Aid.
 |
Ted Landau is the author of Sad Macs, Bombs and Other
Disasters, 3rd Edition published by Peachpit
Press. from which this article is excerpted, was Contributing
Editor for MacUser magazine, and the author of a series
of troubleshooting articles for their "Hands-On"
section. He is author of two previous editions of Sad
Macs, Bombs, and Other Disasters, is a past winner of
the BMUG Choice Product award, and has received critical
praise from virtually every respected source in the Mac
community. He also runs the popular troubleshooting site
MacFixIt |
The Material above is copyrighted and appears
here courtesy of the authors and Peachpit Press
|
