10.4.2 not recognizing extra memory module

Hi Joe - Upgrading to 10.4 is coincidental to your issue, which is hardware related. As a troubleshooting step, you should try swapping out the RAM modules to see if you get the same error with the other module in the lower slot. If you do, the RAM slot or its connection to the logic board has failed and you will need to send your machine in to have the logic board replaced.

Good luck.

Tuttle

Hey Joe you're aren't the only one going through this. Many PowerBook users are also affected by the memory failure.
see:
http://discussions.info.apple.com/webx?128@@.68ab7b77

hopefully you have applecare since most likely your logic board is fried.

Hi Saul -

most likely your logic board is fried.

I think that terming the logic board, "fried" overstates the issue. In fact, the logic board itself is probably in good working order, thus its ability to report on the state of the lower RAM slot. The real issue is the quality of the connection from the lower slot to the logic board--essentially a bad solder. This connection can't be resoldered, so the logic board needs to be replaced.

Tuttle

Many of the users who are unwilling or unable to replace the logic boards on their own dime have reported that they have successfully exchanged the 512MB modules in the upper slot for 1GB modules, leaving the lower slot empty. A 1GB module should cost between $100-$200.

Tuttle

Hi Joe,
The exact same thing happened to my 15" PowerBook only last week - about ten days after upgrading to 10.4.1 ....I have had to have a new 1GHz logic board fitted at a cost of £600 because my machine was out of warranty. At the moment, Apple do not seem to be interested in what is fast becoming the most 'popular' reason for Logic Board Replacement!
It is always the lower memory slot that fails and NOT the upper. If your machine is still under warranty, then of course Apple will replace the logic board free of charge - if not, then it's your credit card that takes a hit ..!
Good luck
voicebox

I am using 10.3.9 and have have 2 x 512MB RAM chips installed for over 12 months. Just recently my lower slot is not recognised and when i have run TechTool Pro 4 it tells me the slot is empty. This problem has just occurred during normal usage and not after OS updating. I have no warranty and i would like to regain the level of memory that i was using.
I have read that you could try swapping the modules from the top to the bottom. I know the lower module is good i have tested it in another PB of same spec's.
Any information would be appreciated.

I have just upgrade to 2x512 MB RAM last week. It worked fine for a week. After that, I just found out that my lower slot is empty. I tried to swap the modules from the top to bottom. Well, it works fine for a while. After reboot, the upper slot is empty again. I took my PB to the Apple care, and replace the board for testing twice, and I replace my memory twice too. Any information update would be appreciated. Thank in advance.

Just recently my lower slot is not recognised and when i have run TechTool Pro 4 it tells me the slot is empty. ... I know the lower module is good i have tested it in another PB of same spec's.

Just based on what you wrote, it sounds like your lower memory slot is toast. If you want to regain the level of memory you had before (2 x 512 MB), then you will need to either get the lower slot fixed (possibly entailing a replacement of your logic board), or remove the functioning 512 MB from the upper slot and replace it with a 1 GB stick.

Hi JagJag,
The same thing happened to me after upgrading to 10.4.2 from 10.3.9 ...
You will not be able to regain the level of memory you were using without replacing the logic board, on the other hand using just a 1GB memory stick in the upper slot is not a satisfactory solution. I too was out of warranty and the cost for a replacement was just over £600 here in London ....! This logic board problem is on going and many people are experiencing the same problem - you will find other threads if you type 'Logic Board' into the search box at the top right-hand corner of this Discussion Page and click search.
The problem is always with the lower memory slot on 15" PowerBooks .... Some people have replaced logic boards under warranty ...others, like you and I, have not been so fortunate!
Apple's silence on this is quite deafening!
Good luck
voicebox

Yeah, same here....G4, 1.25Ghz, 2 512M modules. I upgraded to 10.4.2 and noticed that the lower slot wasn't recognised. However, I have another problem in that there is no startup chime on my machine, and hasn't been for a while, even when I had 10.3 installed. I did manage to get the ram recognised once after reinstalling the chips, and then the chime came back!! No luck since then however!! Is the logic board really the culprit?

My PowerBook showed this fault in its second week. It seems a logic board replacement is the common way to address this. The repair of this fault, for your information, is not covered outside of warranty.

Okay, so my lower memory slot has failed. The Logic Board has to be relpaced, i am outside of my warranty. If Apple replaces my Logic board with a new Logic Board and no solution to why the Lower memory Slot failed, why would i pay for a replacement Logic Board to risk the same thing happening again. I have read from other threads 2 or more Logic Boards being replaced to no result.
Until this problem is regonised by Apple my only realistic option is to spend money on a single 1 Gig Memory chip to regain my Powerbook's operating level.
I was planning to insatll 2 Gig of RAM at some stage, but now my Powerbook's Ram is limited by a fault that has not been recognised. Pity.

"However, I have another problem in that there is no startup chime on my machine, and hasn't been for a while"

Same problem with my PowerBook G4 - 1.5GHz - 512MB, only since the chime problem (not hearing it any more) has the problem with not recognizing the lower memory slot. Not certain if the two problems are related. So it seems from the discussions hear there are two solutions, $600 to repair, or purchase more memory to run in the upper slot. I do have to agree that it would be futile in my opinion to pay for the repair if the same problem emerges again, (as has been reported, at least in the forums,) meaning it could cost $1200 to fix (maybe).

"I think that terming the logic board, "fried" overstates the issue. In fact, the logic board itself is probably in good working order, thus its ability to report on the state of the lower RAM slot. The real issue is the quality of the connection from the lower slot to the logic board--essentially a bad solder. This connection can't be resoldered, so the logic board needs to be replaced."

This statement actually makes more sense then anything I have read so far.

The loss of the chime is indeed releated to the lower slot not working, Larry. Usually though, when you remove the RAM from the lower slot, your chime will return.