Power Macintosh 7500 Symptom Charts - 30
System Hangs
Refer to this table if your system intermittently hangs (freezes) during normal oper-
ation. Note: if your system only hangs when using a specific application, the problem
is most likely with the application and not with your iMac hardware or system soft-
ware. If this table does not solve the problem, refer to the “Software Troubleshooting”
manual on Service Source (under the Troubleshooting tab) for more comprehensive
information.
Possible Cause Possible Fix
System Extensions causing
a conflict.
Boot with Extensions off by holding down the Shift key
during startup. (See TIL article #14343 for more
information on possible Extension conflicts.) Does the
system startup successfully with Extension off?
Yes: Begin adding back the system Extensions one at a
time and starting up the system after each addition. If
the system freezes again, you know that the last
Extension you added is causing the problem.
No: Go to the next step.
Corrupted system soft-
ware.
Boot from the system CD that came with the unit. Does
the problem recur?
Yes: Go to next step.
No: The system software is most likely the problem.
Reinstall system software. (You must use the system
software CD that came with the unit to get the correct
version of Mac OS.)
Bad USB device. Turn off the computer and disconnect all USB devices.
Next, power on the system using the power button on
the front of the unit, and begin adding back the USB
device one at time, beginning with the keyboard and
then the mouse, and so on. If the system hangs only
after you reconnect a particular USB device, replace
that USB device.
Bad memory. Run MacTest Pro in loop mode overnight to test for bad
memory. If MacTest Pro finds a bad memory module,
or other hardware, replace the hardware in question
with a known-good module.
Bad logic board. Replace the logic board.