The Computer Guy's TroubleShooting Pages

The Startup Process
How your Macintosh starts up. How that process can go wrong - the "Sad Mac", the "Flashing ?", stalls, freezes and error messages.


Updated 8/28/99

 Understanding a process and it's design can improve your chances of diagnosing and solving a problem. (not only with computers, but autos and plumbing, also)

Welcome to Macintosh - to - Finder
8. Loading Fonts
Until the release of System 7.1, fonts were stored as recources within the System File. Now the System stores fonts inside a "Fonts" folder within the System Folder. During the startup process, the fonts are loaded alphabetically from the "Fonts" folder before other extensions are loaded. The System can only address 128 font files or suitcases, if there are more than that installed, only the first 128 can be used.
Symptom: Dialog Box - "Extension Conflict Restart with Extensions Off" BEFORE any extension icons appear.
&emdash;Cause: Damaged Font.
&emdash;Repair: Replace font with known good copy. Note: Fonts that are managed by Suitcase, ATM, Font Juggler will not produce this error message at this point, as their fonts are not loaded until their extension is executed.
9. Loading Extensions and Control Panels
Once the mac has loaded the system, enabler, and fonts, it begins to load the Extensions contained in the Extensions folder. Extensions load alphabetically. Extensions modify or add to the code already loaded. For example, when the system draws a button, it uses a specific set of instructions stored in the system file. An extension may be loaded that "patches" this code, so that when the mac wants to draw a button, it uses a different set of instructions stored in the resource. Extensions can be very useful, but because they modify the system code, they can cause problems if they are not written properly. They can also "conflict". If two extensions patch the same code, they may conflict with each other and cause a crash, freeze, or bomb.
This may occur as the extensions are loading, or after the Mac has booted and calls the modified code for the first time. Extensions can also conflict with the OS itself if they are not written correctly.
Loading Control Panels
The Control Panels are loaded next and usually function exactly like extensions; they modify or add to the system software. They can also cause crashes, freezes, or bombs. The only difference is that they typically have an interface to control their function. Double-clicking a control panel opens this interface and allows you to customize the control panel. Some Control Panels are used to change what is stored in the PRAM. The Monitor control panel, for example, is used to set the monitor size, position, and color depth, as well as the location of the menu bar and startup dialog box. The Date and Time control panel is used to set the system clock. Finally, some control panels modify preference files. The Views control panel modifies the "Finder Preferences" file and controls how the finder displays files.
Extensions and Control Panels can often cause problems; because of this they can be disabled easily during startup. After the "Happy Mac" appears, holding down the space key will prevent the system from loading the control panels and extensions. The startup dialog will indicate this by saying "Extensions Disabled".
10. The Finder uses the Desktop file on the volume to draw the desktop.
If the startup application was the Finder, it opens the Desktop file on the startup volume in order to draw the desktop. When it finishes with the startup volume, it looks for any disk volumes that need to be mounted. If there are any, the volumes specified are mounted (by the ROM) and the results passed to the Finder. If a mounting operation fails for any reason, the bad result will be passed to the Finder. At that point the Finder puts up the "This disk is damaged" alert and asks if the volume should be initialized or ejected. If ejected, the driver for that volume still exists, but the volume is unmounted.
Device Problems at Finder
Symptom: Multiple drive icons appear on the desktop for the same drive.
&emdash;Cause: SCSI ID conflict.
&emdash;Action: Check that all devices have unique SCSI-ID numbers that range between 0 and 6, depending on the number of SCSI buses installed. Note: some older devices (especially scanners) are not compatible with SCSI Manager 4.3 and newer Mac models with multiple SCSI busses
Symptom: Drive does not mount.
&emdash;Cause: Can be just about anything &emdash; setup, hardware, or software.
&emdash;Repair: Check cables, power, SCSI ID, termination; try updating hard drive's SCSI driver with drive-formatting software, run Norton Disk Doctor, TechTool Pro, MacMedic, or Disk First Aid v8.2 or newer to verify thedisk..
Symptom: "Disk is full" message when you know the disk is not full.
&emdash;Cause: Corrupted disk-data structures; invisible or temporary files.
&emdash;Repair: Run DiskWarrior, Norton Disk Doctor, TechTool Pro, MacMedic, or Disk First Aid v8.2 or newer to verify the disk.
Symptom: Drive mounts, but you cannot use it as the startup disk.
&emdash;Cause: Bad boot blocks, bad System file, or drive-hardware problem.
&emdash;Repair: Reinstall Apple System software; check hardware connections; run recovery program.
Symptom: A dialog box says, "This disk is unreadable Do you want to initialize it?"
&emdash;Cause: Corrupted data structure.
&emdash;Repair: Do not click on OK! Run Norton Disk Doctor, TechTool Pro, MacMedic, or Disk First Aid v8.2 or newer to verify thedisk.
Symptom: A dialog box says, "This is not a Macintosh disk. Do you want to initialize it?"
&emdash;Cause: Corrupted data structure.
&emdash;Repair: Do not click on OK! Run DiskWarrior, Norton Disk Doctor, TechTool Pro, MacMedic, or Disk First Aid v8.2 or newer to verify thedisk.
Symptom: A dialog box says, "This disk needs minor repairs. Do you want to repair it?"
&emdash;Cause: Corrupted Desktop file.
&emdash;Repair: Click on OK to rebuild Desktop file - suggested to then use TechTool to completely replace Desktop.
For each volume that the Finder sees, it opens the Desktop file on the volume to get the information that it needs to build the desktop. If the Desktop file is not found on a volume, it is created. If ,there are any errors while creating or using the Desktop file, the Finder will display the "This disk needs minor repairs" message. If the OK button is clicked, the Finder will delete the old Desktop file (along with any Finder Comments in it) and create a new one. If that fails, the volume is unmounted and deemed unusable by the Finder. This can happen if the disk is locked or too full to add a Desktop file. If that disk was the startup volume, the computer is rebooted since the System was forced to unmount the startup volume, and cannot run if there is no startup volume.
The Finder is an application like any other Mac application, but it is central to the operating system. The Finder is the application with which you interact with the operating system; you use it to find, open, copy, move, and delete files. It is also the application that you use to open Control Panels and Desk Accessories, restart and shut down the computer, and unmount storage devices. The first thing the finder does is mount any storage devices that are connected to the computer and check their desktop files. If the desktop files are outdated or if the and keys are depressed, the Finder will rebuild the desktop files of the connected storage devices.
Immediately after the Finder loads, the mac opens any files that are in the "Startup Items" folder. Applications, files, folders, and aliases can be kept here if the user wants them to be opened every time the mac is turned on. If the user does not want the startup items to be loaded, they can be bypassed by holding down the shift key immediatley after the Finder loads. Some applications (like "Stickies") load and then switch themselves into the background, leaving the Finder as the active application. Other aplications will not. Once all the Startup Items have loaded, the mac has finished the startup process.
ToolKit Required to Repair Listed Problems
Emergancy Startup Floppy, CD, or Cartridge
System Install Disks or CD
Instructions on opening Mac Model
Tools for opening the case
Known good SCSI cables (system cable, adapters for various ports)
Specifications for Mac Model - RAM (speed, installed singly or in pairs, size order in slots, etc)
Logbook of past installations, bombs and upgrades
Newer Techologies' GURU or Apple's Apple Spec Database
Hardware tester - TechTool Pro v2.11 or Ramometer (from Gauge Series - Newer Technology)
Techtool v1.18, Disk First Aid 8.2 or newer, Drive repair utility (DiskWarrior, Norton Disk Doctor, Techtool Pro, MacMedic, etc)
David Anders The Computer Guy 206-286-8438
Copyright © 1998 David Anders The Computer Guy
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