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Installing New Ram - Imac won't start

Z

zedizdead

macrumors newbie
Original poster
May 31, 2008
6
0
Hello there,

I recently got an 20' 2.4 GHz Intel Core 2 Duo Imac. It came with 1 gig of Ram. I purchased 2 2Gig SODIMM chips from New Egg. The ram specs matches what the little manual says. ddr2, pc2-5300 667MHz. When I install the new chips, the mac won't start. Period. No beeps, no nothing. I can sort of hear it try to start, then quits.

When I put back the original ram chip. Works again.

When I have the original ram chip AND 1 of the new chips (for a total of 3 gigs of RAM) it works.

Swapped one new chip with the other (as long as the original is in) Works.

Original Chip is on the right side, New is on the left. Swapped places. Works.

The mac will start ONLY if the original is in place. I should be able to start it with the nes ones in but it won't. I know both works because I swapped them.

Anybody have any ideas on what's going on? Is there a setting somewhere I need to change or something?

Thanks!
 
One other thing I forgot to mention, if i only have 1 of the new chips installed and NOT he chip that came with it, it won't work.
 
Best guess: your new RAM has incorrect SPD programming. The machine works when the original RAM is in, because it can read the SPD of the Apple RAM and set the timing of the memory bus. But with only one or two of the new RAM, there is no valid information, so the Mac determines there is no RAM it can use. (BTW: What brand of RAM did you order?)

Send the RAM back. If the company is any good, they will replace it for you with tested Mac-compatible RAM at no charge for shipping. If not, demand a full refund.

As mentioned, it's safest to deal with a reputable, Mac-aware seller who will guarantee compatibility.
 
does it have a different number of "black squares/boxes" on the chip than the original RAM chip?

if so then you got the wrong "density" RAM chip
 
Thanks guys for the input.

To answer some specific questions:

The ram is some a company called Patriot, and on the packaging i has the little MAC logo so I thought would work. I got it from Newegg.com so returning them will be easy.

As far the the black boxes on the back of them, they are the same. But on the new chips they are a little bigger.

The SPD sound like the best explanation. When I look into the system profiler there is all kinds of info for the mac ram and not as much for the Patriot ram. Although it does say Status: ok. Looks like I'll be returning these. Thanks for your help.
 
I always throught crucial.com was everyone's favorite for mac-compatible RAM. More often than not, crucial.com memory is what Apple sells as Apple-brand memory and is what's included from the factory in Macs. Crucial.com is also close to being the cheapest memory you can buy...
 
You went with Patriot, that's your problem.


I recommend Samsung or Crucial. I went with Samsung cause it was cheaper at the time.
 
Jrb599 said:
You went with Patriot, that's your problem.


I recommend Samsung or Crucial. I went with Samsung cause it was cheaper at the time.
Click to expand...

Patriot's just a ram maker. some patriots modules use samsung memories on them. I think he got the wrong type of memory. I bought OCZ and it works great in my imac 24" alu.
 
anubis said:
I always throught crucial.com was everyone's favorite for mac-compatible RAM. More often than not, crucial.com memory is what Apple sells as Apple-brand memory and is what's included from the factory in Macs. Crucial.com is also close to being the cheapest memory you can buy...
Click to expand...

Apple never has, and never will, use Crucial memory. Crucial is a retail brand.

Crucial is owned by Micron, Apple buys some, not most, of their RAM in bulk from Micron. But it is not Crucial branded.

Most often you will see Hynix and Samsung RAM in Apple factory configurations.
 
imac123 said:
does it have a different number of "black squares/boxes" on the chip than the original RAM chip?

if so then you got the wrong "density" RAM chip
Click to expand...

Wrong. The 'black squares/boxes' have nothing to do with the density of the RAM. Those are the RAM chips. The more you have (one or two sided) the more memory you have.
 
zedizdead said:
Hello there,

I recently got an 20' 2.4 GHz Intel Core 2 Duo Imac. It came with 1 gig of Ram. I purchased 2 2Gig SODIMM chips from New Egg. The ram specs matches what the little manual says. ddr2, pc2-5300 667MHz. When I install the new chips, the mac won't start. Period. No beeps, no nothing. I can sort of hear it try to start, then quits.

When I put back the original ram chip. Works again.

When I have the original ram chip AND 1 of the new chips (for a total of 3 gigs of RAM) it works.

Swapped one new chip with the other (as long as the original is in) Works.

Original Chip is on the right side, New is on the left. Swapped places. Works.

The mac will start ONLY if the original is in place. I should be able to start it with the nes ones in but it won't. I know both works because I swapped them.

Anybody have any ideas on what's going on? Is there a setting somewhere I need to change or something?

Thanks!
Click to expand...

It it one of the older style imac's. They will only except 3 gig max. That's way it works when you have the original chip and a 2 gig chip set in. It won't work with 4 gig in it at all. You'll only be able to upgrade to a max of 3 gig.

Bufordt
 
thecrackerjack said:
Wrong. The 'black squares/boxes' have nothing to do with the density of the RAM. Those are the RAM chips. The more you have (one or two sided) the more memory you have.
Click to expand...

Umm... with a given capacity of memory module (say, 1 GB), you can make that with 8 x 1024 Mbit chips, or 16 x 512 Mbit chips. The 16 chip version would be described as low density.

It doesn't matter for Intel macs, but G4s and earlier are pretty specific about the density of the modules they require.
 
Same here

The same is happening to me, but with kingston RAM, the exact same behaviour.

However my brother has 20" Imac and they work very well on his Imac.

What could it really be?
 
Jrb599 said:
You went with Patriot, that's your problem.

I recommend Samsung or Crucial. I went with Samsung cause it was cheaper at the time.
Click to expand...

Nope. Same thing happens with Crucial. I just encountered the exact same problem, and the Crucial forum has a bunch of reports of the same thing.

Now in my case, the original RAM is 667 MHz and Crucial sent an 800 MHz part. Crucial reps are telling people in the forum that this is the problem, but they've been saying that for years and in 2011 they're still selling the wrong part (it's the only one offered on their site for this iMac model). So they're deliberately wasting people's time.
 
iMac won't start either

I'm having the same problem as everyone above. I've done the switch-a-roo thing and it works fine with a 1 & 2 G installed but when I switch out the 1 for a 2 it starts but won't boot.

Everymac and XScan both say that I can add another Gig of ram (FYI it's an iMac 7.1)

http://www.everymac.com/systems/apple/imac/stats/imac-core-2-duo-2.4-20-inch-aluminum-specs.html

I personally installed the last 2G card and the new one is exactly the same thing. Since it works with either the old or new 2G I'm completely baffled.
 
Bufordt said:
It it one of the older style imac's. They will only except 3 gig max. That's way it works when you have the original chip and a 2 gig chip set in. It won't work with 4 gig in it at all. You'll only be able to upgrade to a max of 3 gig.

Bufordt
Click to expand...
Ah the OP has the same iMac as my wife's iMac and it is reading the full 4 GB that it has had in it since it was 3 weeks out of the box in 2007.
 
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