Memory Problem


My G5ppc. has 8 gigs of ram. But after checking "About this Mac", it shows that I now have only 7 gigs.
So I checked with the System Profiler and it shows that Dimm2/13 & Dimm3/J14 are at 512MB each instead of 1GB.

Then I ran the Apple Hardware Test disc & it reported " Error detected at startup" and it showed " Error code: post/0/2048/Dimm3/14". What does that code mean and how do I fix it?
post/0/2048/Dimm3/14 error simply means that Dimm3 in slot J14 is not passing the power on self test (POST)

First step when memory is not recognized properly, is to try reseating all of your memory sticks.
If you haven't done that recently, it's a good plan - and may fix your issue.
I would remove all the memory sticks, then -firmly- reinsert back in the same slots. The only exception is for Dimm3 in slot J14. Swap that one with another that is currently not reporting a problem. I might choose to swap that with Dimm1.
Run your AHT again after reseating all the memory sticks. If Dimm1 now reports an error, replace that one, or (even better) replace the pair that were in Dimm2 and Dimm3 slots.
I think it's likely that a simple reseat of all the sticks will clear the error (it often does)
Thanks!!! I'll give that a try. I looked for the slot numbers on the circuit board. They are marked 4,3,2,1 then 1,2,3,4. Since the System Profiler's list was: DIMM0/J11, DIMM1/J12, DIMM2/J13, DIMM3/J14, DIMM4/J41, DIMM5/J42, DIMM6/J43, DIMM7/J44. Can I assume that if
DIMM0/J11 is #1 on the first section of slots on the circuit board, then DIMM3/J14 should be the slot marked #2 in the second section of slots on the circuit board?
I don't have an 8 slot G5 here, so I am going to make some guesses.
Dimm0 is the topmost slot (marked 4, highest slot on the logic board),
OR (guess 2):
Dimm0 is the top center slot (marked 1 on the upper bank)
That makes Dimm3 as either slot 1, or the second guess, is slot 4 (still in the upper bank of 4)

So, how to proceed? Here's what I would do:
Do NOT move any RAM sticks, except for upper bank slot 1 & 4. Before you swap any sticks, reseat ALL the sticks, but be sure to place each stick back in the same slots. AND - test your system. I would look at each stick, to make sure that each pair is the same manufacturer. If the sticks are all the same capacity, then perhaps they were all bought together, and are already same manufacturer.
Pairs of RAM (same capacity, same manufacturer) should be installed in pairs, working out from the center slots: Slots 1 are a pair, slots 2 are a pair, etc. DO NOT move the sticks unless you need to - keep track of any changes that you make. Just for troubleshooting, don't make a change in stick slot, unless you first try moving those 2 (swap upper bank slot 1 & 4) that I mentioned first. One of those will be the Dimm3/J14
Most important, is to reseat (without moving the sticks between slots), and test your PowerMac to see if that's all you need to do.
If that doesn't help, THEN try to swap the upper bank slots 1 & 4. and test again.
If you STILL get boot errors, or the memory is not recognized properly, come back with the error.
OK, it will probably be awhile before I get back to you. I'll have to follow your advice after I get home from work. But I'll be back.
Well I pulled all the sticks in the upper bank as you suggested. I saw these tiny little markings on the circuit board. They were on the right side of the slots directly above the locking mechanism. So I got my magnifier & low and behold there were those markings! So here they are:

The upper bank: 4 is J44, 3 is J42, 2 is J14, 1 is J12. The lower bank: 1 is J11, 2 is J13, 3 is J41, & 4 is J43. I hope this layout will help anyone else that has this problem. I rebooted from the Apple Hardware Test disc & it passed!!

Thank you again!!