G5 PPC Memory Slots?

Hi. I'm running a G5 PowerPC 1.6 (four memory slots), and OS 10.5.6

Lately I've had a lot of Gray Curtain crashes, regardless of the application I was using. These crashes came earlier and earlier until the machine was crashing almost immediately after startup. I became so frustrated that I backed up my drive, erased it, and tried to reinstall a clean OSX. No good. The install failed every time. I suspected hardware malfunction.

I then ran Apple Hardware Test (Extended), and sure enough it reported a memory error:

2MEM/2/4 DIMM1/J12

To confirm the error, I took out the memory sticks and reinstalled them in different order, then ran Hardware Test again. As expected, it reported a memory error again, but in a different slot:

2MEM/2/4 DIMM0/J11

So, I'm pretty much convinced it's a bad stick. But, before I replace it, I wanted to check with you guys about the numeric order of the memory slots. My old G5 has only 4 slots (2 in each bank), and I'm not sure if they are in numeric order from the top to the bottom, or from the bottom to the top, or what? Doesn't appear to be labeled on the board itself.

What's more, I'm not sure if Hardware Test STOPS TESTING when it encounters an error...so, unlikely as it may be, I don't know if I have more than one bad stick.

Any advice, guys? Gracias!

DocVelocity said:

So, I'm pretty much convinced it's a bad stick. But, before I replace it, I wanted to check with you guys about the numeric order of the memory slots. My old G5 has only 4 slots (2 in each bank), and I'm not sure if they are in numeric order from the top to the bottom, or from the bottom to the top, or what? Doesn't appear to be labeled on the board itself.

Click to expand...

Regardless of the order of the memory slots:

- just run the hardware test
- find out which dimm slot contains the bad memory
- open the computer & remove the bad memory
- close the computer
- rerun the hardware test

If you pulled the appropriate bad memory stick, you're good to go. If you pulled the wrong stick, then get back in there and pull the correct one.

You only have 4 memory slots...the worst that can happen is you do this 4 times!!! But I'm sure your better than that, and you'll probably get it right the 1st time.

Good luck,

- Nick

I think the G5 needs memory in pairs, so you will need to pull pairs.

Memory in G5 have to but removed or installed in synchronized pairs.

do not try to run it with just one of a pair in or you'll damage you computer