One DIMM socket randomly does not see RAM

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One DIMM socket randomly does not see RAM

Hey, I've got MPBu late 2008 and recently I've found it's running really slow - I was quite shocked when I saw that one DIMM socket was empty (system profile->memory). Of course it wasn't. I've got into my dimms, plugged RAM out, plugged it in again really hard (with clicks). I also swapped it, to see if "empty dimm socket" will differ in future or not.
It was 2GB again, running fine for like a week but then again my mac has frozen during wake from sleep (no cure for that, I know) and after reboot I again saw 1GB only. DIMM0 always see RAM, DIMM1 is randomly having "I-don't-see-RAM" problem so it's not RAM fault I suppose.
I've tried resetting PRAMs/NVRAMs etc.

Do you folks have any idea what could it be? Maybe it's reasonable to sold those dual 1GB RAMs, buy single 2GB and live with it? I really don't need that bunch of ram but it would be cool to expand it to 4GB in a future and with that problem it's waste of money 😟

Thanks for any help!

PS Of course I have genuine RAM since I bought that mac in German Apple store. Here's screenshot, maybe it will help. "Puste" means "empty": http://img716.imageshack.us/img716/2526/zrzutekranu20100911godz.png

Message was edited by: misieux

MBPu Late 2008, Mac OS X (10.6.4)

Posted on Sep 16, 2010 2:00 AM

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Answer 1

Sep 16, 2010 6:00 AM in response to misieux

Hey . .

it's easy to isolate this situation by getting the rams in each slot one by one ..If both the rams work in one slot and if both the rams create problems in the other slot it means the slot is faulty and the rams are ok ..

Also keep in mind electrical contact quality is extremely important in these devices..hence the gold plating on the connectors..I would recommend giving the connector 'legs' on the ram modules a gentle rub with a dry cloth a few times to get rid of any dirt-oxidation if any..I would also apply compressed air into the ram slots to achieve the same results ..

if after all this the problem persists I would suspect a hardware failure and take my mac into the apple service before this grows into something else

hope this helps 🙂

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Answer 2

Sep 16, 2010 8:14 AM in response to misieux

Test the individual RAM modules using [Rember|http://www.kelleycomputing.net:16080/rember>.

If both check out, run the extended Apple Hardware Test to make sure there's no problem with your hardware.

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Answer 3

misieux Author

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Sep 16, 2010 12:13 PM in response to misieux

Hey guys, thank you very much for replies.
Murat, I will try to use some compressed air on empty slot tomorrow in work, I forgot how successful sometimes it can be.
I've just ran Rember with result "Total execution time: All tests passed! Execution time: 47 seconds".
I will run Apple Hardware Test in a moment, I still have those 10.5 DVDs somewhere. I didn't knew something like that exists, well - it's never too late to learn something new 🙂
Of course I've ran out of warranty one month ago but I heard somewhere that all notebooks sold in EU must have at least two years warranty (in addition to Apple Warranty), I have to confirm this as it would be great to use it while I still can...
Thanks for now, I will let you know when I clean those slots and run Hardware Test.

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Answer 4

misieux Author

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Sep 20, 2010 11:08 AM in response to misieux

Okey, I think it's all clear now. I did Apple Hardware Test (passed with no problems), I have cleaned slots, nothing - today I got this same problem.
I found some people that were talking about one dead RAM slot in their MBPs - I won't fix logicboard now, it's too expensive - I rather will buy one 4GB RAM (it's getting quite cheap, around €80), put it in the working slot and then I will have 4 or 5 GB RAM (not a big difference as with 2 or 1GB - you can imagine how angry I am at the moment 🙂
I hope nothing more will happen to my logic board, fingers crossed 🙂
Thanks guys!

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Answer 5

Sep 21, 2010 8:03 AM in response to misieux

Hi,
I have exactely the same issue. I also own a late 2008 MBP (the first one with unibody). Randomly there is only one DIMM recognized, then again, both 1GB DIMMS are being recognized.

I started to find out about this by hving issues with waking up from sleep mode. I've done all the tips here, like resetting PRAM and NVRAM etc. Nothing helped.

I bouth my book at a local reseller, and not directly from Apple. And also my one year warranty has expired in Feb 2010. My reseller told me, that after this one year warranty by Apple it's my duty to prove that a maybe defective RAM-slot is my obligation. Not quite sure if that confirms either with EU-Law or German Law.

Nevertheless, is the only way to find out if a slot is defective to swap the DIMMS as mentioned above?
I really have no interests in paying 600-700$ for a new logic board. Since my maschine was bought Feb last year and is only being used stationary at my home office...

Regards!

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Answer 6

eww

Level 9

53,052 points

Sep 21, 2010 10:07 AM in response to Moritz-Alexander Lebrecht

Nevertheless, is the only way to find out if a slot is defective to swap the DIMMS as mentioned above?

That's certainly the easy way, and I don't know any other. Test each module in each slot with the other slot empty. If each module works properly in one slot but not in the other, then one slot is bad.

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Answer 7

misieux Author

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Oct 28, 2010 2:43 PM in response to misieux

Hey guys, I have some feedback in that issue.
I still don't know WHY one of my slot is bad, but a lot of problems were gone since I had get rid of one RAM.
I've decided to upgrade from 2x1GB to 1x4GB. Looks like 1GB instead of 2GB wasn't only problem. Since I got rid of RAM in defective slot my macbook started to sleep or shutdown properly. The freeze on wake issue was a big problem to me and looks like emptying defective slot was really helpful.
(And NO, that wasn't iphoto screensaver. Freeze on wake was much more problematic to me before than just screensaver 😉

Take care guys & hth

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