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Purchased Mac Pro 2,1 and need advice on repair

ptdebate

ptdebate

macrumors 6502
Original poster
Jul 3, 2014
333
4
Dallas, Texas
Good morning all,

I was able to buy a 2007 "8-core" Mac Pro 3.0 GHz from a guy on Craigslist for only $80. Of course, there's a catch--the system has no ram or hard drives and is not guaranteed to be functional.

Luckily, the diagnostic LEDs 2 through 5, which would indicate a problem with the CPUs, remained off when the DIAG_LED button was pressed. The lights for trickle power and power supply were appropriately lit as well.

So, I so far have a case, a good power supply, a graphics card, and good CPUs and logic board (?).

I powered on the system with no ram and it flashed the power LED on the front indefinitely, which I understood to signify that the system couldn't boot due to a lack of RAM. I'd also purchased some no-name FB-DIMMs from Fry's to test it out--the Mac seemed to not even recognize they were there when I installed them, continuing to flash all the red LEDs on the RAM caddies when powering on.

Here are the DIMMs I tried:

http://www.frys.com/product/7963870?site=sr:SEARCH:MAIN_RSLT_PG

So, finally, here are my questions:

Is it more likely that the RAM is bad or incompatible or that the RAM caddy itself has a faulty connection? I'm suspicious of the fact that the RAM was stripped at all--the seller said the Mac was from his office, but why would it have been stripped in such a way unless there was something wrong with the logic board?

Which brings me to my next question: if I was able to get positive feedback from the diagnostic LEDs, does that mean that I can rule out the logic board being bad?

Any other advice on how to proceed would be greatly appreciated. Also, if anyone has extra Mac Pro drive caddies they'd be willing to sell me, I'd greatly appreciate it.
 
adam9c1 said:
Try it in all the slots?
I'd find a manual for the unit and see which are the slots.
1 and 2
or 1 4
Click to expand...

There's an installation diagram on the inside of the removable panel that indicates DIMMs are to be installed in slots 1-2 of caddy A first. I tried this as well as other configurations and could not get the Mac to "see" the RAM.
 
Update on RAM

I made arrangements to buy eight OEM 512MB FB-DIMMs from a guy later for a pretty good price. I'll try them out and see if I'm able to get a chime.
 
New RAM in--no change from before

I installed the new RAM and moved the risers around--still no chime. I also still get the rapidly flashing light above the power button.

Any thoughts on how I should proceed? RAM clearly isn't an issue.
 
Possibly the GPU?

I also noticed that the GPU LED does not illuminate. Does that mean that the problem is possibly caused by a bad GPU? I tried removing it and it made no difference, but it is my understanding that Xeon processors have no onboard video and thus the Mac wouldn't be able to boot without a GPU.
 
Has anyone experienced any of the above problems? Again, I have a steadily flashing power LED and no chime. RAM is good and diagnostic LEDs don't indicate any specific problem, although the GPU one isn't illuminated.

UPDATE: USB bus does NOT read inputs. Can I safely assume that the logic board needs replacement? I have my eye on one on eBay for $200. Is that a pretty good deal?
 
Went ahead and bought a new PRAM battery. It kind of feels like I'm having a conversation with myself at this point :/. Here's to hoping the battery fixes it!
 
ptdebate said:
Went ahead and bought a new PRAM battery. It kind of feels like I'm having a conversation with myself at this point :/. Here's to hoping the battery fixes it!
Click to expand...

Hello , I'll do my best to get your MP 2,1 on line long distance .

You seem to have a lot of bad ram :-( Not uncommon . Also , the new modules you bought seem compatible but low quality . low quality ram causes a lot of problems in Mac Pro workstations . Do not skimp on this . New is not necessarily good . Used is not necessarily bad . Obtain quality used enterprise grade modules . I can provide model numbers later .

Your last set of memory modules are not compatible . Or memory riser(s) have failed .

Indicated by power button light flashing .

Obtain two known good memory modules and install them in slots 1 and 2 of riser and install riser in upper riser slot in the Mac .

Don't assume your Mac has a dead logic board . Your ram is not working at this time . It is not passing POST .

If known good memory has been installed and your Mac does not pass POST , then replace the memory riser .

If known good memory modules have been installed and known good riser(s) have also been installed and your Mac still does not pass POST , we will take it from there .

gotta do this step by step ... takes time .
 
ptdebate said:
Went ahead and bought a new PRAM battery. It kind of feels like I'm having a conversation with myself at this point :/. Here's to hoping the battery fixes it!
Click to expand...

I wouldn't worry too much about battery failure in the (Intel Mac era) Mac Pro . This is not the 68K era , where a nonworking battery might be suspect in a failed boot attampt .

Mac Pro batteries live long .
 
Thank you for the response, Machines! :)

I suspect it must be the memory risers, if you are indeed certain that's the culprit and not the logic board or power supply. The reason i know it would be the risers and not the ram itself is that I returned the cheap ram I got from Fry's and instead used some OEM memory I got used and had tested in a different system.

I should note also that the red LEDs on the risers flash once upon power up but do not stay illuminated.
 
Last edited:
ptdebate said:
Thank you for the response, Machines! :)

I should note also that the red LEDs on the risers flash once upon power up but do not stay illuminated.
Click to expand...

Do all the eight (four on each riser) red lights on both risers light up briefly with your newly bought memory modules during start up ? And then do not remain lit ?

As Apple would say "That is expected behavior."

As I would say "Now you tell me..."

Let's try something from scratch .

Populate DIMM slot 1 in both the memory risers with matching memory modules (same capacity and model) . Leave unpopulated all other slots . Install both memory risers . Start up your Mac . Verify that all red lights flash on the risers (one for each of the eight modules) . If they all do , then likely your memory risers are good . If any lights on the risers stay on , then either bad ram or bad riser , or both .

Let me know what happens .



I still suspect this is a memory module failure .
 
If you send me your address via pm, i'll mail you 2 sticks of 512 ram that were replaced with new ram, but this is STOCK nanya ram that was shipped with the unit, i've got no problems helping you out :)
 
zfxp said:
If you send me your address via pm, i'll mail you 2 sticks of 512 ram that were replaced with new ram, but this is STOCK nanya ram that was shipped with the unit, i've got no problems helping you out :)
Click to expand...

That's super nice of you! Wow! I will do right now :)

Machine, I'll report what happens after running the tests you recommend!
 
Save yourself some time and look for replacement logic board.
Symptoms indicate that northbridge on you current mobo is shot.
 
666sheep said:
Save yourself some time and look for replacement logic board.
Symptoms indicate that northbridge on you current mobo is shot.
Click to expand...

Hmm. Is the northbridge where the connectors to the memory risers are located? Can I effectively rule out the power supply based on the information I've gathered so far? Thanks!
 
Northbrigde contains memory controller. If LEDs on risers flash once when machine is powered on, it would mean that RAM gets powered. It's unlikely that both RAM risers failed in the same time.
If you're sure that memory you try is OK and you have swapped risers (upper to lower and vice versa), next suspect is the northbridge. Especially when you're getting flashing power LED.
 
ptdebate said:
Hmm. Is the northbridge where the connectors to the memory risers are located? Can I effectively rule out the power supply based on the information I've gathered so far? Thanks!
Click to expand...


You are jumping the gun , here .

We need to deal with the memory issue . There is a reason why your Mac's power button is flashing ... ram is almost certainly the reason . Verify you have at least two known good memory modules in your possession .

If you have a failed logic board , because of a failed Northbridge chip , it might be possible for you to re-thermal paste that chip . (It could be an overtemp issue . The NB getting too hot since the paste has evaporated after 8 years . The safeties would automatically shut down the Mac . Which is why I don't think it is a NB chip issue . Your Mac is not automatically shutting down .) Access to the spring release of the NB heatsink is on the rear of the logic board - requiring removal of the logic board for servicing . In case you need to deal with it . Might save you the cost of a new logic board . Helpful hint ... if you buy a replacement 2006 MP logic board , the paste on the NB chip is likely also to be from 2006 . That is not ideal .
 
Machines said:
If you have a failed logic board , because of a failed Northbridge chip , it might be possible for you to re-thermal paste that chip . (It could be an overtemp issue . The NB getting too hot since the paste has evaporated after 8 years . The safeties would automatically shut down the Mac . Which is why I don't think it is a NB chip issue . Your Mac is not automatically shutting down .) Access to the spring release of the NB heatsink is on the rear of the logic board - requiring removal of the logic board for servicing .
Click to expand...

That's all BS. You don't know what you're talking about, sorry.
 
Machines said:
Get off this thread
Click to expand...

Because you said so?

I've built over five hundred of the cMP , many of them from scratch .
Click to expand...
Uh, oh...

I guess none of them was 2006-2008, otherwise you'd know how to access and remove NB heatsink in those (hint: does not require removing logic board, no rivets with springs there).

I'm ignoring you from now on and everyone else should too .
Click to expand...

But, in case if you'd want to learn something: NB could overheat if it will pass POST at all. Not before.
 
I once had a memory riser crap out for no reason. Never knew why.

Chances of 2 dying at same time are ZERO. So, ask yourself honestly if there was any RAM weirdness leading up to this?

Ideally you would have a friend with same machine and try RAM and risers in that.

Might be cheapest to find a CL special. Scratched and dented but otherwise functional 1,1. You could figure out problem via swaps and have parts you need with no chance you bought wrong parts.
 
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