Macbook pro can't work with 667mhz ram

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Macbook pro can't work with 667mhz ram

Hi. I would like to share with you my macbook's recent strange behaviour asking for your help.

I have Installed 4GB ram on my Macbook pro 4.1 includes 1 memory card ddr 667mhz and the second as ddr2 800 mhz.

Recently I successfully repaired my laptop with reballing -not the trick with the over,it repaired with the official way- .The laptop used to work with a pair of dd2 667 mhz ram but finally ended up with the previous memory set-up (667,800 mhz).

Today,I tried to boot up my laptop and the machine denied it.When I press on, it works for 3 seconds and then it switches off.When I remove the 667 Mhz (notice, this kind of frequency is the default for this model) and try to start ,It works without closing in the third sec but it doesn't boot up at all,because it freezes in a black window without the start up chime,that means that there is obviously a hardware problem.I tried several ram combinations including one pair of 1 gb 667 mhz ram with actually not luck.

Therefore,my question is why the computer doesn't turn on with the default type of ram and it works only with the 800 mhz one that is not.

About the principal issue,I'm able to give it back to service while I'm on the 3 months guaranty.

Thanks in advance for your help.

P.

MacBook Pro, Mac OS X (10.6.8), 4Gb ram

Posted on Apr 5, 2014 2:33 PM

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Answer 1

a brody

Level 10

85,314 points

Apr 5, 2014 2:44 PM in response to peterpanx

Macs can only work with RAM designated for their age.

Looking up MacBook Pro 8,1 on http://www.everymac.com/ says it is an Early 2008 MacBook Pro. That's what you need to look for through http://www.crucial.com/ or http://www.macsales.com/

Do not get RAM that says by speed, timing, chip size, ddr size, hz size, as that will not match you up with the correct RAM. Only getting RAM by Early 2008 MacBook Pro will reliably work. ValueRAM will not work well either.

And the best RAM has a lifetime warranty.

If you have other Macs, use this link as a guide

https://selfsolve.apple.com/agreementWarrantyDynamic.do

to find out which time of year and year your Mac is by model number or http://www.everymac.com/ if you lack a serial number.

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Answer 2

peterpanx Author

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Apr 5, 2014 3:49 PM in response to a brody

Thanks for your reply.

I know that I had to use the right mhz ram type,but we lost the one of the two ram modules,so I had to use one 667 and a second 800 MHz. As a result, the laptop decrease its frequency from 800 to 667 as most of the laptops use to do in this case.Although I run a memory test when I did this setup with no problems.

Eventually the particular problem is that my mbp didn't not seems to work with 667 ram but only with the 800 one.

This kind of issue is very strange.

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Answer 3

OGELTHORPE

Level 9

57,329 points

Apr 5, 2014 4:02 PM in response to peterpanx

A MBP model 4.1 can accept up to 6 GB RAM with the following specifications: 200-pin PC2-5300 (667MHz) DDR2 SO-DIMM. The best sources of Mac compatible RAM are OWC and Crucial.

Note: No MBP ever specified 800 MHz RAM.

I suggest that you install the correct RAM for proper performance.

Ciao.

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Answer 4

a brody

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85,314 points

Apr 5, 2014 4:39 PM in response to peterpanx

Macs have always been extremely particular about their RAM. Not all 200-pin PC2-5300 (667MHz) DDR2 SO-DIMM are compatible. Only the ones rated for Early 2008 MacBook Pro are compatible with Early 2008 MacBook Pro. Any variance, and you will likely run into problems. Even the ones that are Early 2008 MacBook Pro may have issues, but the likelihood is much less.

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Answer 5

peterpanx Author

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Apr 6, 2014 12:10 AM in response to OGELTHORPE

As i wrote before,i install the default ram : KINGSTON DDR2 5300 (667 MHZ) 1 Gb which was installed in my computer when i bough it and eventually, the machine does NOT work.It works only with. KINGSTON DDR2 2GB 800.

And here is the problem,that it doen't recognise the proper ram...

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Answer 6

OGELTHORPE

Level 9

57,329 points

Apr 6, 2014 3:56 AM in response to peterpanx

Macs have had a reputation for being very selective in regards to RAM. Even when the specifications are 'correct', RAM from some vendors are found to be unsatisfactory. Hence my suggestion of OWC and Crucial as sources for the most reliable RAM for a Mac. I have RAM from both and have not had an issues as have many others.

Do a search on these forums for past discussions on this subject and you will find this to be the case.

Ciao.

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Answer 7

peterpanx Author

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Apr 7, 2014 7:19 AM in response to peterpanx

Let me correct something in here,At my first, post there is a typing mistake.However,the correct ram module that my laptop used to use was a ddr2 667mhz and ddr2 800Mhz.

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Answer 8

OGELTHORPE

Level 9

57,329 points

Apr 7, 2014 7:45 AM in response to peterpanx

I cannot give you a definitive answer why the 667 MHz Ram does not work and the 800 MHz does. I have to assume the former module is faulty for some reason as RAM is prone to fail on rare occasions.

Even though your MBP works with the 800MHz RAM, I still would replace it with RAM with the specifications that Apple calls for. All I can suggest that you encountered circumstances that constitute a very rare coincidence.

Ciao.

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Answer 9

peterpanx Author

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Apr 7, 2014 8:29 AM in response to peterpanx

I have already check the ram modules in several laptops and they work pretty fine.

On the other hand,The only logical consideration until now is that the GPU is faulty again hence the laptop wasn't able to boot up.This kind of behavior,the black screen without bell chime is known to me.I got it when the GPU previously broke down.I'm thinking logically,that the Logic Board losts a part of it body (GPU) and, therefore, behaves strange.

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Answer 10

a brody

Level 10

85,314 points

Apr 7, 2014 11:31 AM in response to peterpanx

Are all those other notebooks the same age, and the same model? If they aren't that means nothing what you have done. It only means those notebooks are less sensitive to the type of RAM. Just because the RAM works in another notebook, does not mean it will work in yours which is either of a different age or a different model.

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