Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

jannikmeissner

macrumors member
Original poster
Dec 17, 2014
32
3
London, UK
I am currently upgrading an early 2012 to 6 Core CPUs (washer stack method) and I have experienced some oddities:
It does boot, but it shows a red diagnosis LED/ red lamp next to the front (when having the tray inserted) CPU. However, in system profiler it shows slots 1 and 2 as empty (which contain RAM Sticks that are known good)

So, my question is if anyone knows which slots belong to which CPU (or A or B as per the labelling on the board)? And does anyone know if slots 1,2,3 etc in the system profiler have the same numbering as printed on the board?


My apologies if this was answered before and I was "just searching the wrong way" meaning typing the wrong keywords into Google and the forum search.

UPDATE:
I tried to tighten the tension until on CPU B until the red light was gone, but then it refused to boot. I then released the screws by 1/8th turn and it booted, but the right light was back...
Also, I now have 5/6 Ram Slots report, with Slot 2 showing empty and Slot 1 showing ECC Errors.

it also doesn't seem quite stable at the moment.

UPDATE 2 [SOLVED:

It seems it was CPU A. After adjusting the screws on that, all memory now reports on A and the the Red LED between CPU B and RAM Slots 1-4 is off. I suppose it was a RAM LED.

So, my conclusion is that CPU A is Slots 1-4 and B is Slots 5-8.
 
Last edited:
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.