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wily · Jul 1, 2004, 09:14 PM

Mac: G5, Dual 2.0

Memory: 512 onboard, 2 Mushkin 512's, 2 Crucial 512's total: 2.5 gig

Problem: Application problems - crashes, gray screen, etc.

Diagnosis: Techtool says Crucial RAM is bad.

Cure: Crucial replaces RAM - no problem!

Uh-oh: Well, it's doing it again.

The likelihood of TWO sets of Crucial RAM being bad is NIL.

What's going on? Can RAM SLOTS go bad??

memory-minus · Jul 1, 2004, 09:34 PM

Originally posted by wily:
What's going on? Can RAM SLOTS go bad??

Doubtful without full logic board failure. If the RAM slots were "bad" they most likely would not see the RAM in them.

Just keep swapping the RAM in and out of your machine until you uncover the bad stick(s). May take a few hours but this is the pain of hardware diagnosis. Don't rely on TechTool as the final word for all for hardware problem diagnosis. When in doubt, swap your RAM.

wily · Jul 1, 2004, 10:22 PM

Ok, now Techtool reports that it passed.

Applications are quitting...hmmm. Maybe this is software.

Any ideas anyone?

memory-minus · Jul 2, 2004, 05:35 AM

Originally posted by wily:
Any ideas anyone?

Did you try swapping the RAM? What were the results?

Edit: to clarify, did you try removing one pair of RAM at a time and booting to see if the symptoms cease? That is really the only sure-fire way to diagnose bad RAM.

wily · Jul 2, 2004, 07:17 AM

Memory -

Yes - you're right and yep, did that.

Waragainstsleep · Jul 2, 2004, 08:45 AM

You have 5x512MB Sticks? I thought they had to be installed in identical pairs. Take out the odd one and try it. Unless your 512MB on-board is 2x256MB? In which case, ignore me.

Is it reporting only one of the Crucial sticks bad? If Techtool can tell the difference between the two crucial sticks apart (IE it always reports the same stick bad, even if you just swap the two crucial sticks around), then it may be that the 2nd one is bad.

Try another utility, see what that says about RAM? Maybe there's a shareware RAM test?

Ideally, try your RAM in another G5.

Detrius · Jul 5, 2004, 08:34 AM

First of all, Tech Tool Pro is far from reliable as a RAM check. Run the Apple Hardware Test that came with your machine.

Also, *YES* RAM slots can go bad without a total failure of the logic board. Also, sometimes reseating the RAM modules makes the errors go away.

If you can't narrow it down with the utilities available to the general public, take it to your local Apple Authorized Service Center and have them run Apple Service Diagnostics on it. It may take a day or so to get a full answer (from switching RAM around and running the tests again), but that's the best test available.

TTP has passed a lot of RAM that ASD has said is bad. Do not rely on TTP. (It's great for hard drive tests though)

wily · Jul 5, 2004, 11:39 AM

Ran Apple Hardware Test and all turned out well.

So, I'm left with the thought that this is a software issue.

Any thoughts on what/where to look/start?

(thanks Det...)

Detrius · Jul 9, 2004, 10:07 PM

Originally posted by wily:
Ran Apple Hardware Test and all turned out well.

So, I'm left with the thought that this is a software issue.

Any thoughts on what/where to look/start?

(thanks Det...)

Oh, sorry I didn't mention this before... sometimes RAM problems are buried deep and don't always show up in a single pass. I don't recall the loop command for Apple Hardware Test, but there is a way to do it. I would recommend letting that run on extended overnight. If it still says you are okay, it's probably not the RAM.

Next (or first--whichever), look for /Library/Logs/panic.log. If in that file, it makes references to com.somebrand.something, then that could point you in the right direction. (could be software or hardware)