G5 bad memory slots

rob morsberger · #1 May 20th, 2009, 05:06 PM

Hi,
I'm having this issue with my G5 dual 2, 10.4.11
I have 1 gig sticks in each of the 8 slots. I recently became aware
that I am only accessing 6 gig. System profiler tells me all sticks are ok:
however, it is showing 512 sticks in slots J13, J14, J43, J44. (Again, they are in fact 1 gig sticks). Apple Hardware test implicates J14 and J44, with this error message: post/0/2048 DIMM3/J14, DIMM7/J44
By various means I have determined that my memory sticks are fine. I've swapped them out and tried them in various slots. The sticks in the bad slots work fine in other slots, etc etc. So I'm certain it isn't the RAM. Also, they are paired correctly.
I am also certain that it isn't a seating issue...I've seated and reseated many times, I pretty much know what I'm doing.
So what else could it be?
Everything else passes the hardware test ok.

One last thing; last night I pulled all the sticks and reseated them and accessed 8 gig successfully for the rest of the evening. Today no dice.

Really appreciate any help!
Thank you,
Rob

djackmac · #2 May 21st, 2009, 12:33 AM

You say you have paired them correctly. If any other sticks you are using are failing or not showing in the same slots every time, thats a bad logic board. I've seen that happen before on those models. If it gets bad enough it eventually might boot to no video with the power LED blinking at you like it has no RAM(seen a few of those also). I've also seen like you are talking about with the chips reading smaller than they actually are.

rob morsberger · #3 May 21st, 2009, 09:03 AM

thanks a lot, I really appreciate the help. I'm afraid that what you are saying sounds right. But: the logic board passes the apple hardware test. If the logic board were the culprit, wouldn't you expect it to fail the test?
Thanks again.

djackmac · #4 May 21st, 2009, 04:09 PM

I've seen tons of bad logic boards, and only 2-3% of the time they were actually bad enough to fail any diags. Also, being a service tech I use the Apple Service Diagnostics that are only available to Apple Service Providers.

rob morsberger · #5 May 21st, 2009, 05:24 PM

Thank you again for your help. I'm shopping for a mac pro.
Much appreciated.
Rob