G5 a1047 memory vs G5 M-series memory

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Level 1

20 points

G5 a1047 memory vs G5 M-series memory

Well, I found out that memory for a G5 M-series,though it's pc3200 ddr400, unbuffered, etc, does not live happily in a G5 a1047 Mac. I went and got PC3200 memory, ddr4000, non-buffered, and the minute I put it in it ran fine for a week, then I started getting the 3 blinky lights...incompatible RAM. When I looked on the box (geil memory), it said it supported only M model Macs (and yes all the specs matched the memory in my G5 2.7). I didn't know there was an A model, only M models of G5's.

So I bought Crucial RAM, using the online memory selector, and it doesn't work either. 3 blinky lights...

***** because Apple says only their RAM works in the machine (yeah right).

So how do I know I'm getting memory for the a1047 when ordering online, or buying locally, when even Crucial's site doesn't seem to care?

Dual G5 tower Mac OS X (10.4.6)

Posted on Jun 16, 2006 10:06 AM

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Answer 1

The hatter

Level 9

61,031 points

Jun 16, 2006 10:16 AM in response to macgiant

Two things to try first off:

Boot into Open Firmware and reset nvram.

Try with just the new RAM.

When you swap memory, nvram doesn't always get 'updated' and resetting nvram will make sure it does.

#1 boot into Open Firmware to Reset NVRAM
#2 run Memtest 4 when possible
#3 Read this: MacIntouch: Bad RAM

And you used this: Crucial G5 2.7 ?

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Answer 2

macgiant Author

Level 1

20 points

Jun 16, 2006 1:50 PM in response to The hatter

Thanks hatter,

Hadn't thought about the nvram. I'd been having other issues with it, kernal panics, then system freezes. So took it to Apple and they found nothing. Took it home put in the crucial ram, back to problems. Did another archive and install. nothing. then removed all usb stuff. nothing. then took out all fonts except the one's osx installs. still the occasional freeze. did a clean install of osx. still freezes. so I tried swapping the apple for the crucial and no startup at all. also tried with ram from chip merchant and geil...still no luck. put the apple ram back in and it seemed to be okay last night, this morning when it came on, lock up and fans. I did notice when I originally switched ram, it was very hot to the touch. almost too hot. So I took it to Apple, and they figured the memory manager on the logic board was going wonky. I should have my Mac back on Monday when the board comes in. Then I have to go get some new memory (the other ones got fried by the computer). That was $600 in memory (though I do get to return the crucial and the geil).

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Answer 3

macgiant Author

Level 1

20 points

Jun 16, 2006 1:51 PM in response to macgiant

and yes it was the crucial g5 2.7.

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Answer 4

The hatter

Level 9

61,031 points

Jun 16, 2006 3:20 PM in response to macgiant

Any time that hardware configuration is changed, do the nvram reset in OF first.

It helps even when swapping/exchanging disk drives, where sometimes the new drive doesn't show up in DU.

It helps where the new RAM doesn't show it is there, until you use the extra RAM, but not regularly.

Swapping or changing PCI cards can according to ATTO result in corrupted NVRAM.

And I don't think the old PRAM/NVRAM "ZAP" routine (and "urban legend to do 3 or more restarts while holding down the keys) is effecient or fully clears nvram and device tree.

Odd about the Crucial memory. And someting "new" from last year.

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