I refer to "Repair Permissions" as superstition, but placebo is accurate, too. Repairing the directory structure will not resolve anything. It's clear from the OP that the machine would not chime.
Here's what's potentially useful: Check the Console for "Previous Shutdown Cause". Check for every time it shut down on you. Anything negative is likely a problem on an iMac (-60 on a laptop just means the battery died).
Also, SMART is far more useful than you think. What makes people think it's useless is that people and programs are looking at it not knowing what it means, and therefore, programs are telling you that your drive is fine, even though the actual SMART data plainly says it's not (because the manufacturer doesn't want to replace a drive every time it gets bad blocks). The thresholds are intended to tell you whether catastrophic drive failure is imminent within the next 24 hours. It still has info telling you that the drive is acting up in a less severe manner.
Okay... you talked me into it. Here's a little tool I've been working on for a while that I use to find potential issues in log files. I've attached it in double-clickable format. The included copy of smartctl was built on a 10.7 machine, and therefore, I'd expect it not to work on 10.6 or older. Don't panic; every machine has errors. In reference to the OP, the relevant info will look somewhat like this:
Code:
Summary of shutdowns and sleeps encountered
shutdown: count : description
5 : 6 : (normal shutdown or sleep)
3 : 2 : (normal restart or power button forced shutdown. Expected normal behavior)
0 : 2 : (battery/power disconnected. Expected normal behavior)
-128 : 3 : [COLOR="Yellow"](not known. Did it boot from a different OS? Potentially normal behavior)[/COLOR]
The script will check the SMART status and tell you if there are any pending sectors, reallocated sectors, or errors in the drive's own internal SMART log. A drive that doesn't know it's bad will look like this:
Code:
##########################################################################
####################### Checking SMART Status of Drives ##################
##########################################################################
smartctl 5.42 2011-10-20 r3458 [x86_64-apple-darwin11.2.0] (local build)
Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
EDIT: Oh, and it will check all attached SMART-capable drives, but it only shows success for the first drive. It will notify you if any other internal drives have potentially bad SMART status.
The source code is here:
https://github.com/whschultz/Diag
