Level 1

9 points

Mac Pro 3.1 not booting after ram install

Hi Everyone,

Before my troubles started I had 2x2gb in riser board A and 2x2gb in riser board B and everything was working fine.

However today I came to install 2 new 4gb modules by placing them into slots 1 & 2 of riser B and placing the 4x2gb modules into riser B and now it's all gone horribly wrong!😟

When I turned on my mac the fans went into overdrive but i still managed to get into my account but could only see 8gb of the 16gb installed.

I then shut down took out the new 4gb modules put back everything back as before and restarted but this time it powered up but there wasn't even a boot sequence!

I've tried switching the boards around and even tried an SMC reset but all to no avail .

I'm totally stuck and not sure what to do next can anyone please help?

OS X El Capitan (10.11.3), Nvidia Geforce GTX 670 • BenQ FP241W

Posted on Oct 6, 2016 9:51 AM

22 replies

David Mahony Author

Level 1

9 points

Oct 6, 2016 1:21 PM in response to lllaass

Ok here's what's happened...

As suggested earlier I put the the new modules into slot 1 of both risers and the Mac booted to the login screen BUT, the fans were now running at full blast!

Youre right about the heatsinks heres some photos of what I have...

https://www.dropbox.com/s/mlundu3goo64xks/Old%20Ram.jpeg?dl=0

https://www.dropbox.com/s/2hvh96eelmpd06b/New%20Ram.jpeg?dl=0

Old ram on the top link and new ram on the other....sorry I could get photos to upload.

Maybe it is I have the wrong type of ram

lllaass

Level 10

210,519 points

Oct 6, 2016 1:25 PM in response to David Mahony

Macs are picky about memory, especially with mixing different manufacturer's memory

David Mahony Author

Level 1

9 points

Oct 6, 2016 1:41 PM in response to lllaass

Its so frustrating, I've wasted hours today - Oh well, I'll have to pick up with the suppliers tomorrow.

I'll report back to this thread once I have some replacements but in the meantime thanks everyone for your valued advice.

Eau Rouge

Level 8

42,656 points

Oct 12, 2016 2:08 PM in response to David Mahony

Ok so if you are still having problems with the new RAM and you feel it may not be the right spec for the 3.1, try and get a refund, cross-fingers.

You could have a look at Mr Memory's RAM for the 3.1 I bought RAM from them, albeit a while ago but have not had any problems with it. https://www.mrmemory.co.uk/memory-ram-upgrades/apple/mac-pro/2008-2.8ghz-quad-co re-intel-xeon

David Mahony Author

Level 1

9 points

Oct 12, 2016 2:13 PM in response to Eau Rouge

I ordered some ram from Mr Memory and installed it yesterday and it works a treat!

Having said that on a couple of occasions when booting I did get a no entry sign on a gray screen but I'm not too sure what that means.

Today it seems to be working ok with no issues as yet so fingers crossed!

That was a good recommendation thank you so much.🙂

Oct 12, 2016 9:21 PM in response to David Mahony

The prohibitory sign says, "while trying to load the known basic components of the kernel, and one was damaged or missing".

You buddies at the Apple support communities say, "That drive may be getting flaky". If you don't already have a Trusted backup, you will need one soon. (Post back if you need any help with that).

David Mahony Author

Level 1

9 points

Oct 12, 2016 9:22 PM in response to Grant Bennet-Alder

Thats what I was suspecting as I've just installed a Samsung Evo 500gb SSD to replace it but I'm having problems so I'll start a new thread for that.

Really appreciate the help guys..thank you!🙂

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Mac Pro 3.1 not booting after ram install