Macbook Santa Rosa - will not work with 4GB RAM. eh...?

[Moriarty]

I just recently upgraded my 2.2 GHZ Santa Rosa (GMA X3100) Macbook to 4GB RAM.

...well I tried.

Unfortunately the machine will not boot. I turn it on, hear the optical disk drive grind away, the sleep light comes on, the hard drive turns on, and that is it. Completely and utterly nonresponsive.

So I take out 1 of the 2GB modules and replace it with one of my old 1GB modules. The system boots up fine and recognises 3GB. Now I think "hmm... looks like the other 2GB module is defective!". So I put back the 2GB module I took out and remove the other 2GB module, replacing it with another 1GB. And my Macbook boots up fine again, recognising the 3GB.

So if neither of the 2GB modules are defective... why will my machine not boot up!? :confused: The Santa Rosa Macbooks officially support 4GB. Even if my computer was an older GMA 950 Macbook, it should still recognise 3.2GB or something.

Anyone know what is going on? Right now I'm running fine on 3GB, but I'm a bit annoyed right now. Lucky my warranty lasts until 2nd February...

[Cboss]

That doesn't make any sense. Only a few days ago I upgraded the same Macbook to 4 GB RAM and it is working great. Maybe you didn't get one of them inserted the entire way? I found I really had to push to insert mine.

[Moriarty]

That doesn't make any sense. Only a few days ago I upgraded the same Macbook to 4 GB RAM and it is working great. Maybe you didn't get one of them inserted the entire way? I found I really had to push to insert mine.

They are inserted fine. If one module wasn't inserted right, I am sure the machine would boot but only recognise the correctly inserted module.

If it helps, the RAM is DDR2-800 (it was cheaper than DDR2-667 :p). But that shouldn't matter, because DDR2-800 is backwards compatible with DDR2-667, the RAM just runs at the lower speed.

[SnowLeopard2008]

I think it is the speed difference. I upgraded the same model MacBook (it's my main computer) with DDR2-667 MHz memory and it worked without a hitch.

[Moriarty]

But 800MHz memory is backwards compatible! And 1 module of it works fine, just not both modules!

Anyway, I emailed my repair agent and he says he has seen this before when putting DDR 800 in a 667 MHz machine, and to try using 667 modules. I'll try getting two 2GB 667 MHz sticks and see how it goes.

Perhaps it is something to do with the faster RAM requiring a slightly higher voltage, and both modules of 800 MHz go above the motherboard's tolerances. However I would have thought this would be compensated for by the fact it is clocking down to 667 MHz.

Anyway, I'll see how it goes once I get some 667 MHz RAM.

[jav6454]

But 800MHz memory is backwards compatible! And 1 module of it works fine, just not both modules!

Anyway, I emailed my repair agent and he says he has seen this before when putting DDR 800 in a 667 MHz machine, and to try using 667 modules. I'll try getting two 2GB 667 MHz sticks and see how it goes.

Perhaps it is something to do with the faster RAM requiring a slightly higher voltage, and both modules of 800 MHz go above the motherboard's tolerances. However I would have thought this would be compensated for by the fact it is clocking down to 667 MHz.

Anyway, I'll see how it goes once I get some 667 MHz RAM.

In MacBooks, you have to get the RAM speed specific to the module or it will not work properly. Your repair man is right. It has nothing to do with voltage, it is a simple mismatched RAM issue with the main board.

[Moriarty]

In MacBooks, you have to get the RAM speed specific to the module or it will not work properly. Your repair man is right. It has nothing to do with voltage, it is a simple mismatched RAM issue with the main board.

You didn't read my post properly. One 2GB DDR2 800MHz module plus one 1GB DDR2 667 MHz module works fine and registers as 3GB, passes the Apple Hardware Test.

You can't get more mismatched than that, and everything works fine. The problem only starts when I try to use both 2GB 800MHz sticks. Which in my mind rules out a software incompatibility, leaving only the possibility of something physically not working, ie, faster RAM having a higher power draw, higher than the Macbook supplies. Makes sense to me...

[logana]

You didn't read my post properly. One 2GB DDR2 800MHz module plus one 1GB DDR2 667 MHz module works fine and registers as 3GB, passes the Apple Hardware Test.

You can't get more mismatched than that, and everything works fine. The problem only starts when I try to use both 2GB 800MHz sticks. Which in my mind rules out a software incompatibility, leaving only the possibility of something physically not working, ie, faster RAM having a higher power draw, higher than the Macbook supplies. Makes sense to me...

You are correct - sort of.

The reason that it works with a 667 and an 800 is that it can down-speed the faster chip to 667. With 2 x 800 chips it cannot and does not work. The 800 chips work fine, normally, in the MacBooks prior to the Santa Rosa chip.

Can you return the RAM ?

[petrus19]

I have exactlly the same problem.
My memory is from a Kingston kit and works at 667Mhz.
If one of the modules is inserted with one of the old ones...they are detected, and i have 3G of RAM.
If I insert just one or two of the new ones alone (without one of the old modukes), the laptop does not start. Have you solved your problem?

[js81]

And I have a similar problem. I have 2 x 2GB (667MHz) and 1 x 1GB (800MHz). I can use the 2x2GB and its fine, but if I throw the 1GB (800MHz) in with either of them, it won't boot. I was hoping to steal one of the 2GB's to put in my HP Mini, but the HP's 800MHz stick won't work in the Macbook. Oh well - guess I'll have to keep my 4GB. :D

[Eidorian]

There might be something up with the timings on the DDR2-800 sticks. This problem was well known on the later Penryn Macbooks.

My Late 2007 MacBook is working perfectly with 4 GB of G.Skill DDR2-667 since December 2007.

[Gonchallo]

Hi guys,

I have exactly the same problem has Moriarty, mine is late 2007 and suppose to get 4 gb of ram and only works with 3.

I would like to have a solution, and please someone can give me help on this!!!

Macbook Black 2.2 500gb 3gb Ram
Iphone4 16gb

[libraritine]

Hi guys,

I have exactly the same problem has Moriarty, mine is late 2007 and suppose to get 4 gb of ram and only works with 3.

I would like to have a solution, and please someone can give me help on this!!!

Macbook Black 2.2 500gb 3gb Ram
Iphone4 16gb

Just had the same problem today.

I did quite a lot of research before buying RAM, trying to see if I would have any problems/issues with the RAM. Looks like I did research far and hard enough. Surprised there isn't clear warnings about this.

I have a Santa Rosa Late 2007 model 2.2Ghz Macbook.

I bought 2 x 2gb DDR2 (800MHz) ram. When both were in I just got the blank black screen and the white light.

I put in the 512mb (667mhz) ram with 1x 2gb DDR2 (800MHz) ram and the it works fine. Albeit now only 2.5gb ram not the 4gb I had intended.

Now what can I do? Buy a 2gb (667mhz) ram? Most stores nowadays don't sell that. I have to buy online.