Very Odd Memory Problem Please Help

I made a post earlier asking why it said that I only had a few mb of memory free after startup (something that's only been going on for a day or so) when I had 512 mb of memory installed in my PowerBook. I then saw that it said that I only had 256 mb installed and one of my RAM chips wasn't showing up at all. So I turned off my computer, opened up the back of my PowerBook, took out both chips and put them back in. Turned my PowerBook back on and it said I had 512 mb again. I was happy. Then my computer froze on me completely. So I restarted it and it came on saying I had only 256 mb of memory again. So I repeated the process of taking the memory out and putting them back in and it started up as 512 again...locked up. Restart...512...lock up...restart...512...lockup. And then finally it started up as 256 and it's fine so far. It only seems to lockup on me when it shows I have 512 mb of memory installed. Also, even after I switch the memory chips and it displays 256 mb of memory, it always shows the lower memory slot empty (I'm not sure which slot that is because "lower" changes when you flip your laptop to take the back off). So I'm thinking there's something wrong with that slot. Any ideas?

*note: I put this in this forum as opposed to the PowerBook forum because I originally thought it was a a software problem*

check this out could it be the same situation?
http://www.mac-forums.com/forums/showthread.php?t=17875&page=4&pp=15

iNAP said:

check this out could it be the same situation?
http://www.mac-forums.com/forums/showthread.php?t=17875&page=4&pp=15

Click to expand...

Well their dealings were with harddrive space not reading correctly, my problems seem to either lie with a bad RAM chip or bad RAM slot. Plus, I haven't upgraded to Tiger yet, I'm still running Panther.

Still learning sorry

iNAP said:

Still learning sorry

Click to expand...

No worries, I'm certainly not an expert either, that's why I come on here for help :headphone

Were the Ram chips factory installed by Apple?

Yeah, both RAM chips are the same ones that came from Apple. I haven't taken the memory back off of my PowerBook until today.

hmmmm. Well the easiest fix is this: Is it still under warranty? If it is, give a call to apple or make a trip to an Apple Store and have them deal with it.

What model Powerbook do you have btw?

When you open system profiler, and click on Hardware, then Memory on the left side, what does it read the two cards as?

I know there are programs that can scan the Ram chips and run a sort of diagnostic. I'm not an expert on this so I can't think of any ofhand right now, in a bit I'll google and see what I can find for you.

Were the connections on the cards clean? Did you do just a common sense echeck of them?

What does it show under system memory when you open the activity monitor (hardrive-applications-utilities)?

Have you tried resetting the PRAM? I really doubt this would be related, but sometimes doing that will fix odd things. Just did it on my PB actually. I wanna say the way to do that is to hold command+option+alt+P+R when the system is booting up.

Hmmm... I'll see what else I can do for you. I'll do some research and get back to you on this thread, although it's 1:00 AM here in Michigan, so I'm abt. ready to pass out. Might be a few hours....

hmmm..

Well I stopped in at the Apple store and explained my situation, they didn't give a look to my PowerBook, just said that it's probably the logic board and that I should bring it in again sometime soon so that they can ship it out. I've only had it since last August, so it should be under the initial warranty. The fact that they didn't even look at it sort of makes me not believe 100 percent that it's the logic board though.

To answer your questions though, I have the PowerBook model right before the most recent ones with the trackpad upgrade. And in System Profiler, it doesn't read the lower memory chip, just the upper one. This problem occurs even when I switch the chips. When I take them out, I don't see any obvious connection problems. I haven't done anything with the PRAM, for I am unaware of what that is. Thanks.

Here is an Apple article about PRAM: http://docs.info.apple.com/article.html?artnum=2238

If you scroll down, it tells everything that is contained within that. You won't really notice any difference after you reset the PRAM, but it can sometimes fix odd problems. My Powerbook was moving at a snails pace, I reset the PRAM, and shaboom! My Powerbook was fast as a cheetah again (although it's only a panther).

The logic board would be my first hardware related guess, although faulty ram is another possibility. I'd send it in while you're still under warranty.

Has this been a problem sense you got the PB?

I've only noticed this problem the last few days, I don't think it happened before that. The thing that brought it to my attention was the lack of memory I had free even though I wasn't running many applications.

I'm sort of iffy about sending my PowerBook away to get fixed. There's both personal information and personal items (music, pictures, drawings) that I'd like kept personal, even if it is a total stranger looking at it.

hmmmm. Can you think of anything that would have changed in the last couple days that could have caused the problem? Did you install a new program? change any settings? Download anything?

Did you spill anything on the Powerbook? Drop it? Do something that could have damaged it internally some way? Did you leave it somewhere where this could have happened?

I'm just trying to track down on what could have happened. By no means am I an expert on Ram, but when it comes to logic, I'm pretty strong. Logically, something must have changed for the problem to occur.

I don't recall any recent changes that could have made my PowerBook stop detecting the second memory slot. I do take it to college and back, but it's a fairly easy ride. Other than that, no damage that I know of has occurred.

I would suggest a simple (though time consuming) test to find your problem.

1. Label your memory (using a small bit of tape or writing on something that's already on there) 1 and 2.

2. Define which slot is slot 1 and 2 (by saying that 1 is closer to the i/o panel or power connector or whatever).

3. Using only 1 piece of memory at a time try booting the machine, then rebooting, do whatever it is that causes your machine to error and loose the memory.

4. Rotate. So start with piece 1 in slot 1. Then move piece 1 to slot 2. Then piece 2 into slot 1. Then piece 2 into slot 2. Note any errors.

5. You should now be able to tell if it's the slot that is the problem or the memory stick. According to this if tests 1&2 fail, then it is stick 1 that is bad. If tests 3&4 fail it is stick 2 that is bad. If tests 1&3 fail then it is slot 1 that is bad. If tests 2&4 fail then it is slot 2 that is bad.

6. If its the ram that is bad you can decide about having it fixed/replaced or just buying new ram. But if it's the slot, be sure to have it fixed.

7. If no errors occur (or errors that do not fall into a pattern prescribed above) at any point through this testing you've got more serious issues, not because they're necessarily more expensive to fix, but because they could involve the software, or many other pieces of hardware not directly related to the memory. If this is the case, consider a complete clean install of your OS. This will determine if software is causing the issues. If you clean install and there's still a problem, get your unit serviced.

Little step by step scientific method for determining the problem.

I tried what you said and it seems things weren't what I thought before. Each chip worked in each slot when they were in there without the other chip present. Chip one worked in both upper and lower slots, and chip B also worked in both the upper and lower slots...permitting they were the only memory chip installed. When they are both in, however, it's always slot number two that shows up empty. I'm wondering if the PowerBook is having some problem powering both chips when they are installed together. Any ideas?