Failing PowerPC system...

[Dan Williams]

On Thu, 2008-03-13 at 00:01 -0400, Jarod Wilson wrote:
> So... I have this old dual 800MHz PowerPC system (c. 2001 "QuickSilver" Power 
> Mac G4), and its been sporadically locking up under Mac OS X lately, but to 
> date, hasn't under Linux (though it doesn't get used under Linux as often). 
> Well, tonight, I was going to use it for a PowerPC kernel build, but before 
> doing that, fired up a yum upgrade, which led to a disturbind discovery... 3 
> of the 25 or so packages to be upgraded hit cpio errors unpacking files from 
> the rpms, claiming md5sum mis-matches.
> 
> This, coupled with the lock-ups under OS X led me to try another experiment... 
> And wouldn't you know it, a repeated sha1sum on the same file only gets the 
> correct result roughly 90% of the time. To make it more interesting, I've 
> seen some of the incorrect sha1sums pop up more than once. I'm assuming I've 
> got some hardware failing here.
> 
> So anyone have suggestions for diagnosing exactly what component is starting 
> to fail? My first thought was cpu, then motherboard, and now memory... I 
> figure memory is probably the easiest place to start poking, but is there a 
> memtest86 equivalent for PowerPC? If not, I guess its memory stick roulette, 
> and on to other hardware from there. Open to any and all suggestions...

RAM is definitely the first place to look.  You also might just want to
take the RAM out and firmly reseat it.  That's fixed these sorts of
things for me a few times before.

If you have the original CDs the machine came with, the Apple Hardware
Test CD should have a RAM tester on it.  Unfortunately, most of the
hardware test CDs have special builds only for the machine they came
with, so you can't just use any old one.

Dan