Installing new RAM in imac

[downingp]

I just bought a 1GB stick of Apple RAM PC2 5300. When I inserted the RAM into the imac and started my iMac I didn't hear the chime and it wouldn't boot up. I am assuming I installed it correctly it looks like there is only one way to put it in. Am I doing something wrong?

Please help. Thanks.

 

[Nermal]

What sort of iMac are you using?

 

[downingp]

I am using an Intel 20" imac with 512mb currently

 

[killmoms]

That'd be the problem. You have to install RAM in matched-pairs. Meaning, if you wanted 1GB of RAM in your iMac, you needed to buy 2x 512MB sticks. If you want to use that 1GB stick, you'll need to buy another for a total of 2GB. I believe this is covered in the documentation for the computer—it's a consequence of dual-channel memory controllers.

 

[downingp]

I just took out the 512mb of RAM and installed just the 1GB stick and all I got was a bright flashing light down in the lower right corner.

 

[Eidorian]

That'd be the problem. You have to install RAM in matched-pairs. Meaning, if you wanted 1GB of RAM in your iMac, you needed to buy 2x 512MB sticks. If you want to use that 1GB stick, you'll need to buy another for a total of 2GB. I believe this is covered in the documentation for the computer—it's a consequence of dual-channel memory controllers.

And yet I have 1.5 GB in my iMac Core Duo.

 

[killmoms]

Hmm, I could've sworn matched pairs were required. Oh well, in any case, this sounds like a case of bad RAM (or at least RAM that's not up to par for the machine).

downingp: What brand is it?

 

[downingp]

Hmm, I could've sworn matched pairs were required. Oh well, in any case, this sounds like a case of bad RAM (or at least RAM that's not up to par for the machine).

downingp: What brand is it?

It is Apple RAM built by Micron

 

[Eidorian]

It is Apple RAM built by Micron

Are you sure you're putting it into the slot right? Are the clips closing?

 

[downingp]

The clips are closing because I reinstalled the 512 mb ram correctly and my iMac turned on. I am typing on it right now.

 

[Eidorian]

The clips are closing because I reinstalled the 512 mb ram correctly and my iMac turned on. I am typing on it right now.

Sounds like a bad 1 GB stick then. Hey, it happens.

 

[downingp]

Well I gave it one last try and really pushed the RAM hard into the slot and it worked!! It shows I have 1.5GB of RAM in system profiler.

 

[Eidorian]

Well I gave it one last try and really pushed the RAM hard into the slot and it worked!! It shows I have 1.5GB of RAM in system profiler.

Good work! It's not FULL Dual Channel speed but you will get better then Single Channel speeds.

 

[furious]

more ram is always faster than matched pairs.

 

[mr_matalino]

Hmm, I could've sworn matched pairs were required. Oh well, in any case, this sounds like a case of bad RAM (or at least RAM that's not up to par for the machine).

downingp: What brand is it?

Matched pairs are recommended for best performance...

 

[CanadaRAM]

Matched pairs are recommended for best performance...

2 x 512 is better than 1 x 1 Gb when the total RAM is equal (approx. 6% - 8% improvement, depending on application)

however in the real world,

1.5 Gb total RAM trumps 1 Gb total RAM

 

[thewhitehart]

Yeah, I found putting the RAM into my imac a real pain. I believe the manual tells you to open the latches to get the RAM out, but says nothing about closing the latches to assist in pushing the new RAM in. I subsequently tried shoving it in without using the latches to assist me, only putting them back after shoving the RAM in.

 

[ChrisA]

That'd be the problem. You have to install RAM in matched-pairs. Meaning, if you wanted 1GB of RAM in your iMac, you needed to buy 2x 512MB sticks. If you want to use that 1GB stick, you'll need to buy another for a total of 2GB. I believe this is covered in the documentation for the computer—it's a consequence of dual-channel memory controllers.

You don't need install RAM in matched pairs. You just get slightly better performance if you do. In fact you should stick that old 512 stick in the second slot and make the total 1.5GB

 

[ChrisA]

I just bought a 1GB stick of Apple RAM PC2 5300. When I inserted the RAM into the imac and started my iMac I didn't hear the chime and it wouldn't boot up. I am assuming I installed it correctly it looks like there is only one way to put it in. Am I doing something wrong?

Please help. Thanks.

Three things I can think of:

1) The RAM is not pushed in all the say and not making proper contact.

2) The RAM is broken and needs to be replaced

3) The RAM is the wrong type for your system Make sure you have PC2-5300 (667MHz) DDR2 memory.

One more remote possibility is that you damaged the system while yu were swapping out the memory. You can put the old RAM back in to verify this is not the case.