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Lower Memory Slot - Empty

16938 Views 312 Replies Latest reply: Sep 2, 2006 7:31 PM by Mike Johnson12 RSS
  • Rajesh Sharma Level 4 Level 4 (3,730 points)
    Currently Being Moderated
    Jan 2, 2006 7:02 PM (in response to Philip Robinson)
    A practical intermim measure to consider - Did you pay for the PowerBook using a Credit Card? Some Cards extend your warranty without you knowing. I'd give them a call if you did.
    Powerbook 15 High Res 1.67, Mac OS X (10.4.3)
  • Bob74 Calculating status...
    Currently Being Moderated
    Jan 3, 2006 6:46 PM (in response to Rajesh Sharma)
    I have had this issue now as well since upgrading to the GM version of Tiger. Interesting though, I am unable to use 1gb ram in the upper slot either (in addition to using nothing in the lower one). I can use 256 or 512, but the 1gb versions keep failing. Works for a bit, then crashes. My fan does not come on anymore (since updating to GM Tiger) My startup chime is hit and miss.
    Has anyone else had issues with 1GB RAM not working in the upper slot?

    Also interesting to note, AHT recognizes both slots (no errors listed) and it even recognizes the 1gb chips. When I run the AHT tests, both slots pass as does the memory. As soon as I bootup though, nada...

    For those of you with warranties, stop knocking those of us without. This is apparently a widespread issue that requires Apple's attention. Congrats on buying the warranty, but we aren't all made of cash. Minus this issue, my powerbook has performed flawlessly since I purchased it 18 months ago.
    1.25ghz, Powerbook G4, DVDR, Mac OS X (10.4.3)
  • Rajesh Sharma Level 4 Level 4 (3,730 points)
    Currently Being Moderated
    Jan 3, 2006 11:18 PM (in response to Bob74)
    I don't know if this affects you, or whether you already know about this, but I know there is a thread describing a problem for early Aluminium PB's requiring "bus slewing" ram - as you have a 1.25 you might want to take a quick look at that thread - essentially, your ram has to be capable of responding to changing bus speed "on the fly" - and not all ram does. This is only an issue on the early 1.25s and 1.33s I think.

    Alternatively, could be a duff 1gb stck.
    Powerbook 15 High Res 1.67, Mac OS X (10.4.3)
  • Bob74 Level 1 Level 1 (0 points)
    Currently Being Moderated
    Jan 3, 2006 11:50 PM (in response to Rajesh Sharma)
    Thanks for the suggestion. I did discover another user having this issue. The workaround was to set the processer speed to Highest (instead of automatic etc) This has allowed me to use it for a longer period of time. You may be correct in your thinking though as it still will crash after extended use. I still wish my other slot worked though, then I could just use my 2 512s.....
    1.25ghz, Powerbook G4, DVDR, Mac OS X (10.4.3)
  • Mauro Bertolini1 Calculating status...
    Currently Being Moderated
    Jan 6, 2006 12:30 AM (in response to ggeoffre)
    sorry to hear that its you 4th but it doesn't surprise me with these machines.

    Here is something i found on the web which probably wont help (didnt for me)seeing this is a design hardware issue which physically fries the lower slots (i am onto my 3rd logic board and its also broken).

    i feel i need to add some sort of help instead of continually posting how unhappy i am with this situation and how arrogant Apple are by ignoring it.

    try:

    1. Resetting the NVRAM in Open Firmware:

    - Hold command-option-O-F (that's the letter O) at boot, and continue holding until a white screen with black text appears

    - Issue the commands:

    reset-nvram

    set-defaults

    reset-all

    (The last command here causes a reboot)

    OR

    2. Resetting the Power Management Unit (it's a long shot, but it's worth a try since it's easy:

    - http://docs.info.apple.com/article.html?artnum=14449#faq11

    Dual G5 2ghz & stuffed 15" lower ram slot RIP   Mac OS X (10.4.2)   unhappy with Apple ignoring this issue
  • Mauro Bertolini1 Level 1 Level 1 (0 points)
    Currently Being Moderated
    Jan 6, 2006 12:33 AM (in response to ggeoffre)
    And the saga continues....

    Here is something i found on the web which probably wont help (didnt for me)seeing this is a design hardware issue which physically fries the lower slots (i am onto my 3rd logic board and its also broken).

    i feel i need to add some sort of help instead of continually posting how unhappy i am with this situation and how arrogant Apple are by ignoring it.

    try:

    1. Resetting the NVRAM in Open Firmware:

    - Hold command-option-O-F (that's the letter O) at boot, and continue holding until a white screen with black text appears

    - Issue the commands:

    reset-nvram

    set-defaults

    reset-all

    (The last command here causes a reboot)

    OR

    2. Resetting the Power Management Unit (it's a long shot, but it's worth a try since it's easy:

    - http://docs.info.apple.com/article.html?artnum=14449#faq11
    Dual G5 2ghz & stuffed 15" lower ram slot RIP, Mac OS X (10.4.2), unhappy with Apple ignoring this issue
  • garyd Calculating status...
    Currently Being Moderated
    Jan 10, 2006 8:00 PM (in response to ggeoffre)
    Has anyone out of warranty had any success with Apple? If so, what steps should I be taking?

    PB G4   Mac OS X (10.3.9)   bad lower ram slot
  • Sean Powerbook Calculating status...
    Currently Being Moderated
    Jan 12, 2006 9:12 AM (in response to ggeoffre)
    I just had the same problem after the 10.4.4 update could this be a software problem???
    Powerbook G4 1.5 Ghz, Mac OS X (10.4.4)
  • David Williams4 Calculating status...
    Currently Being Moderated
    Jan 14, 2006 9:29 AM (in response to ggeoffre)
    My PB G4 1.25G is suffering from the 'RAM in lower RAM slot does not show' problem.

    I'm looking to avaoid a repeat once my motherboard has been changed under AppleCare,

    Now just taking a punt here based on my limited knowledge of electronic hardware (I've designed and made my own circuit boards in the past), there's a possibility of heat being involved in the failure of the lower RAM slot connecctor which seems to be the culprit in this problem (The RAM chips work OK in the upper slot, not in the lower slot QED). So the more heat we can get away from the RAM cards and the lower slot connector the better so as limit thermal expansion and heat stress on the solder of the lower connector etc.

    Now right above the two RAM cards is the cover we remove to change the RAM cards, a metal surface in contact with the air. So why not capture as much heat as possible from the RAM chips, and conduct it to the cover panel to keep the lower connector as cool as possible?

    I found some 3M heat conducting tape

    http://www.tevalo.com.ua/cgi-bin/index.cgi?artnr=80-901-36&lng=eng

    which is not electrically conducting.There are two types, one is .13mm thick, and the other .25mm thick (and cost around $80 a metre...)

    Would it be possible to create a heat conducting harness comprising two layers of tape which is fitted as follows

    1) Lower layer of tape is fitted beneath the lower RAM card to conduct heat away from lower side of card and top surface of motherboard.
    2) Fit lower RAM card
    3) Fit upper layer of tape on top of lower RAM cartd, so that it conducts heat away away from upper chips on lower RAM card and lower chips on upper RAM card.
    Both pieces of conducting tape are joined at the lower edge of the chips (the edge nearest you as you replace the chips), and then looped up and stuck to the underside of the memory card cover which is a nice metal surface in contact with the air, and could dissipate the heat from the RAM cards.

    There is about 3mm of room between the edge of the lower RAM card and the side of the cavity the RAM sits in, and about 8mm for the top card. It looks like plenty of room for the tape to fit into as far as I can see.... There is a piece of plastic with instructions on the underside of the cover plate which may impact the thermal dissipation of the plate, but I guess this could be removed, or it may not be a problem

    It seems on the face of it that this modification might help reduce the risk of thermal failure of the lower RAM slot connector

    I haven't tried this, and it may not be feasible, or the tape may not be good at conducting heat along its length. Maybe I have the wrong end of the stick about the nature of the poblem, but it might just be a fix that one of the PBook repair shops could implement (or even Apple... 8-) It could be fitted by anyone who can change a RAM chip.

    I've sent this to a couple of the PB repair shops, so maybe one of them will pick it up? Or if you think this post has merit, forward it to whoever might be interested



    Powerbook G4   Mac OS X (10.4.4)  
    Powerbook G4, Mac OS X (10.3.9)
  • irwe Calculating status...
    Currently Being Moderated
    Jan 15, 2006 1:06 PM (in response to ggeoffre)
    Add another unhappy user.

    Bought my PB in late September and have had a couple of freezes and several kernel panics, and I just couldn't figure out what the matter was. Have two 512s which have been, until today, working properly (System info has reported 1GB all along). Ran Hardware Test today, after the last in the kernel panic series. Result: bad lower slot. Restarted and found out: yes, only 512, in upper slot. Lower slot empty. Same as all you folks above me in this thread.

    Seems like there is no point in getting someone to repair the computer, since most of you have had recurring problems. And I need the machine for my work.

    Question: Am I right in assuming that you can safely continue working only with the upper slot? One or two have reported problems with both slots, but mostly it seems to be working for most of you.

    Best,
    Richard
    PowerBook G4 15", Mac OS X (10.4.4), 1.5 GHz; 1 GB RAM (?); 100 GB HD; SD
  • maltor Calculating status...
    Currently Being Moderated
    Jan 16, 2006 12:29 PM (in response to irwe)
    Hello everybody,

    I am in big trouble with my PowerBook and I am looking for advice. I had occasional kernel panics, especially when I booted the system, ever since I detected that the lower memory slot was missing. I don't know wheter the two phenomena are related, but you might want to be careful.

    After I installed the battery update nothing happend at first. But when I tried to change battery settings two days later the system freezed and I got a nice "white on black" kernel panic. Afterwards I could boot the system, but when I logged in ... kernel panic! The hardware test says "everything fine". I reset the PRAM. I then backed up my data (you shoudl always do, ha ha) and formated the hard disc. Note that I could use the PowerBook as an external hard disc. I tried to install OS 10.3 and 10.4 but could not succeed in either. During the installation procedure (in both cases), the screen turned blue and only this spinning wheel was turning for ever.

    Hardware test gave me the following information:

    Boot ROM version 4.7.1f1
    PMU version 128

    Any suggestions or similar experience? How to set the battery firmware to an older version?

    Best regards,
    PowerBook G4 1.25Ghz, Mac OS X (10.3.9), Lower memory slot is broken
  • Benjamin Earle Level 1 Level 1 (25 points)
    Currently Being Moderated
    Jan 16, 2006 8:19 PM (in response to ggeoffre)
    I'm not sure what the general experience has been with out-of-warranty repairs. I sent Apple a letter the other week, requesting an acknowledgment of receipt at the very least, but so far have not received anything back.

    I've exchanged a couple of phone calls with the law firm handling the class-action suit, but at this time I don't know if I feel comfortable agreeing to attorney representation and the sort. If it goes to court, I would definitely file as a claimant, but I would like to avoid giving a deposition, or being financially responsible for attorney fees should we lose the lawsuit.

    So, at this time, I'm content having only 1GB of RAM. My PowerBook will be two years old in April, I see it lasting maybe another year before it comes time to replace it with the "MacBook Pro."

    On a sidenote: Who the **** is responsible for that name? It sounds absolutely absurd. When the PowerBook went from 68K to PowerPC, it was still called the PowerBook. It has spent 15 years building name recognition, and aside from the combustible batteries in 1995/1996, the PowerBook has a solid reputation. Why mess with it? I'm dreading the announcement of Intel Power Macs, God only knows what those will be called.
    PowerBook G4, 15 Aluminum, Mac OS X (10.4.4)
  • DSL_Steve Level 1 Level 1 (45 points)
    Currently Being Moderated
    Jan 17, 2006 8:39 AM (in response to Benjamin Earle)
    [From MacFixIt.com]

    Fix for memory not being recognized We previously reported an issue where some memory slots (particularly the lower RAM slot on PowerBook G4s) are not recognized after the Mac OS X 10.4.4 update.

    This is a common occurrence with various incremental Mac OS X updates, which can be more picky about RAM than their predecessors.

    As noted in our previous coverage of this issue, the problem may be resultant of a latent logic board problem merely exposed by the Mac OS X update.

    In some cases, the RAM is simply seated improperly. Removing the module, and re-installing it, making sure the connection is tight, has resulted in the previously disabled module working again for several readers.

    Some users are not aware of the issue until they check the "About This Mac" pane accessible via the Apple menu or experience significant slow-down in a particular application

    In other cases, performing a set of open firmware reset routines can result in the memory being properly recognized again.

    To boot into Open Firmware, shut down your Mac, then start it up while holding down the Command, Option, O and F keys. At the prompt, enter the following commands (you may want to write them down on a piece of paper before beginning this process), pressing the return key after each:

    reset-nvram
    set-defaults
    reset-all

    after which your Mac will restart.
    15" PowerBook (High Res, X2DVD), Mac OS X (10.4.4)
  • dejoro Calculating status...
    Currently Being Moderated
    Jan 17, 2006 11:59 AM (in response to DSL_Steve)
    And yet another victim. Noticed a couple of days ago that my 1GHZ, 15" PB (OS 10.3.9) was running slower than usual. Checked Apple System Profiler and, sure enough, it showed the lower memory slot as being empty. (There are two 512mb chips installed).

    I tried swapping the dimms and resetting the nvram in open firmware with no luck.
    PowerMac G5 1.8 GHz, Mac OS X (10.4.4)
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