Mac Pro 2,1 help please

Hi All
Hopefully someone out there can advise me on a memory problem for my Mac Pro 1,1,
The motherboard would not accept a 1,1/2,1 firmware update so I sourced a 2,1 mobo on Ebay and swopped them over everything works OK except if I install 32 gb memory it falls over the two os led's (5+6) on the motherboard showing over temp,
I have tried riser (A) 16gb riser (B) removed it works OK tested running for two hours
I have tried riser (A) removed riser (B) 16gb it works OK tested running for two hours
I have tried riser (A) 8gb slot 1&2 (B) 8gb slot 1&2 fails over keeps rebooting,
so in conclusion both risers are OK and both slots are OK all memory OK.
I’ve tried smc reset
Pram reset
Unless I’ve missed something, I’m baffled the problem must be the mobo as all the other stuff was working with the old 1,1 mobo
Any helpful suggestions of what I can try to solve this.
Thanks Derek

Hi Derek - Welcome to the Forum!

If you have it rebooting when Riser A and Riser B slots 1 & 2 have 4GB each in them (8GB total for a total of 16GB) then all is not okay.

From what I am understanding you have 32GB total in 8 sticks which means 4GB per stick. Right?

If it were me - I would be looking for a problem in one of those 4GB sticks. Unfortunately this will mean some detecting work. I would start by taking each stick and booting from them one at a time.

It is possible for memory to work with the other board and become flakey on the new board. I have had a stick work fine for years and then just quit.

Lisa

lclev said:

Hi Derek - Welcome to the Forum!

If you have it rebooting when Riser A and Riser B slots 1 & 2 have 4GB each in them (8GB total for a total of 16GB) then all is not okay.

From what I am understanding you have 32GB total in 8 sticks which means 4GB per stick. Right?

If it were me - I would be looking for a problem in one of those 4GB sticks. Unfortunately this will mean some detecting work. I would start by taking each stick and booting from them one at a time.

It is possible for memory to work with the other board and become flakey on the new board. I have had a stick work fine for years and then just quit.

Lisa

Click to expand...

Hi
Thanks for your input however I've tried all my ram and all of it works if installed in one riser A or B it only falls over if I use both risers, there seems to be some conflict between the two risers.

Thread moved to Desktop area.

- Nick