inconsistent OSX failures after hard drive replacement

[jconway]

A few weeks ago my Macbook Pro hard drive started to fail and I replaced it. Since then I have had a handful of issues that seem to randomly occur after each boot.

For example, one time after cold boot, the grey screen (apple and gear) will hang forever. If I power cycle, the next boot might work fine, but when I log in DNS does not work. If I boot a third time, Finder fails to start, but DNS works fine. After a fourth attempt, everything works perfectly.

Note that this exact sequence is not predictable -- sometimes the grey screen hangs twice in a row. Sometimes everything works perfectly twice in a row. It seems very random.

I have tried:
1) boot from install DVD (Leopard) and run disk utility to fix permissions and repair the disk
2) upgrade to Snow Leopard, and repeat #1
3) run all updates to Snow Leopard and repeat #1
4) reinstall Snow Leopard and repeat #1

So far, if I am patient and boot enough times, I eventually get to a usable system, but obviously this is not ideal and somewhat disconcerting ;-)

Any ideas, suggestions, questions, etc would be much appreciated!

Thanks,

Joe

 

[djackmac]

How do you know if it was the drive failing in the first place? Do you have any known good RAM to test with?

 

[jconway]

I was seeing file access errors (not permissions but actual failing to read the files), so I am reasonably sure the drive was failing.

As an update, I have run the disk utility to fix permissions again, and although the problems are not gone entirely, they are much less frequent.

I also found that when I run into a boot up with DNS failures, I can "fix" it by running

launchctl unload /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
launchctl load /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

Joe