[X4U] DRAM failure (was Hard drive or hard drive controller gone)

[Jon Warms]

On  Wed, 18 Jan 2006 10:51:50 -0800,
Jim Robertson <jamesrob at sonic.net> wrote:

I have been lurking on this thread through the many postings about
your problem. Now it looks to me like you're thrashing around like a
weak swimmer in water suddenly over his head. Maybe I'm wrong.

But if I were you, I'd start trouble-shooting over again. And I'd start
with the beginning. That is, how does the machine - as Apple shipped  
it - run?

And, according to your post, it still runs pretty well.

In my experience, random hair-pulling failures are often attributable to
a faulty hard drive. Your experience doesn't go against this; when the
MacOS isn't on the hard drive, things go well.

Have you run a verify disk with Disk Utility? What's the S.M.A.R.T.  
value?
If this were my machine, with the results you describe, I would really
check out the hard drive. (Disk Utility has worked for me.)

And when I've ignored unrepairable faults on a drive, it's come back to
haunt me, with weeks of weird failures followed by complete drive  
failure.

At one time, random freezes
and reboots were part of the Mac game, but they've just about  
disappeared
since OS X. If you've gotten rid of all the add-ons (hw & sw), and  
the system
runs ok from the install cd, it sure sounds like a hard drive issue.

In any case, good luck.

Jon

> The weird thing is that it will run for HOURS from the Tiger  
> Install DVD, or
> from Tiger on the internal drive if I'm booted into single-user mode,
> command-line interface.
>
> Eric Morrison suggested resetting open firmware, resetting the  
> motherboard,
> and resetting parameter ram. None of those helped.
>
> So, it's looking more and more like a motherboard problem, but then  
> how is
> it that the machine can pass memtest over and over and over AND run  
> from the
> internal hard drive or from the Intaller DVD without freezing up?