Help! Mac Pro 4,1 to 5,1 x5690 upgrade dimm slots out

[chedro]

I have 3 2009 8 core mac pros (MB535LL/A), two of witch I have successfully upgraded the processor to two 6 core x5690. My last of the 3 mac pro was working fine, and then the dimm slots for processor A went out after several weeks. The computer boots fine and works well. I have torqued the heat sink screws perfectly, as the processors still work and have worked well in my other machines without any hick-ups. I have moved and reseated the ram and tried different configurations with no luck. I've even reseated the processors several times with no luck. I placed the bad processor trey into my other 2009 mac pro, and the dimm slots for processor A did not work. So it must be the processor board?? But here is the kicker, once the old processors (original Xeon E5520) are placed back into the machine the ram and dimms slots work perfectly. I have also seated multiple x5690 processors into the same board, and they all have processor A dimm slots fail.

Any thoughts, suggestions, tips?

Should I just get a new processor board? Buy new ram, although the ram works fine in my other machines.

Thanks much!

 

[DNComputers]

It's probably just a single pin that isn't making contact. I would look really carefully at the socket and see if any pins are bent. If you know which RAM slot and which CPU, let me know, you can get a rough idea of where the bent pin may be at.

 

[chedro]

It's probably just a single pin that isn't making contact. I would look really carefully at the socket and see if any pins are bent. If you know which RAM slot and which CPU, let me know, you can get a rough idea of where the bent pin may be at.

Dimm slots 2,3 and 4. I looked at all the pins and they seem fine. Also, why would the old processors work perfectly if it's a bent pin?

Thank you for your help!

 

[h9826790]

If you use the normal X5690, that may be because when you put back the old lidless processor in, you can tighten it a bit more, and make that pin have contact again. However, you know that you can't over tighten the screw with the X5690, so may end up a little bit loose. It's just my guess.

 

[DNComputers]

I assume you are using lidded X5690s? The difference in how the processor makes contact with the pins. My guess is you just have to tighten it a little bit more, but as I only do delidded CPUs, you should wait for someone more familiar with this problem to answer, wouldn't want you ruining your CPU or board.

If the pin is bent slightly down a different fit may work just fine. You might try swapping the CPUs (move the CPU that's in A to B) and see if the bad RAM slots change to the other side. IF they do, it's the CPU, if it stays the same, it's the socket/pins

I'm not in a place to look this up easily for a little while, but later tonight I will see if I can find anything on this.

 

[chedro]

If you use the normal X5690, that may be because when you put back the old lidless processor in, you can tighten it a bit more, and make that pin have contact again. However, you know that you can't over tighten the screw with the X5690, so may end up a little bit loose. It's just my guess.

Sorry forgot to mention I bought the x5690 delided. The same kind that I used in my other two machines without any problems. The profile seems to be the same. I'll double check the pins again, and post a picture when I have time tomorrow. It's also strange that they lose contact after working fine for several weeks.

 

[DNComputers]

Yeah, they should fit exactly the same, just make sure you're tightening it all the way, which is sounds like you would be, if you've done a few, so I don't think that would be it. This is not something I've run into. Seems really odd that it'd work for awhile, then fail. My suggestion would be when you're in there looking at the pins, if you don't see anything, swap the CPUs, see if the problem moves with the CPU.

 

[avkdm]

Totally unrelated but I too recently found 2 dimm slots (dual mode) not working on an S1150 Board.
After removing the CPU I noticed that one pin was slightly bent, after 3 or 4 goes at straightening and reseating CPU it finally made contact and now all 4 dimm slots work. Be careful though thats a lot of money you are playing with there.
By the way have you tried the ram from your other Mac Pros in there?

 

[kwikdeth]

totally sounds like a pin out of alignment to me. we saw this all the time at an old datacenter job building machines with these CPUs, especially in dual configs. sometimes just one pin slightly out of alignment will cause the whole thing to fail to boot. these things are INCREDIBLY sensitive so you may have to look with a magnifying glass but my money is an out-of-alignment pin.

 

[flowrider]

I had a similar problem when I upgrade my X55590s to X5677s. One of the CPUs would not recognize one of the Dimm slots. I tried moving the Dimms around. But when I switched the CPUs the problem followed one of the processors. I exchanged the errant CPU, and all has been fine since.

Lou

 

[chedro]

I had a similar problem when I upgrade my X55590s to X5677s. One of the CPUs would not recognize one of the Dimm slots. I tried moving the Dimms around. But when I switched the CPUs the problem followed one of the processors. I exchanged the errant CPU, and all has been fine since.

Lou

Yup this looks like the same problem. I moved the processor to the other slot (B) and the dimm issue followed. Now 5, 6 and 7 are out. What's more concerning is this the second processor that has failed, which I have heard is very rare. I'll contact the seller and see if I can get a third replacement.

On the same note, would there be something that is causing the processors to fail after weeks of use? Or am I just the lucky one with two lemons?? Thanks all for the help.

 

[flowrider]

^^^^Yes, it is rare - And I guess you were just lucky☹

Lou

 

[goodfidelity]

Just experienced this same think. one DIMM (5) slot not reading the modules.

Upgraded with lidded processors, i did many of these, first time this happens. X5680.

Solved it with putting larger dimms in the other slots. Using then only 4 first slots, not best configuration.

Overtidghtening the CPUs will make the machin not boot.

//GF