Mac Pro 2009 Issues after NorthBridge Repair

[Jabaar]

Hello everyone! I was doing an upgrade on my 2009 Mac Pro upgraded to 5,1 and noticed the North Bridge was wiggly, so I used some screws, sprints and nuts to re-secure it into place after getting rid of the regular Apple Northbridge holders. However, upon installing the new CPUs and booting - the GPU fans blast at full speed, I am greeted by a black screen and there is no chime. The CPUs I am using are Xeon x5670s.


Now, I noticed that if I only have CPU A installed, the system boots and works well, it is only upon installation of CPU B that this occurs. I’ve used both CPUs in socket A to verify that they are working, so I’m stumped as to what is causing this problem. The pins seem to be in great condition from what I can tell.


If anyone can shed some light on this it would be greatly appreciated!

 

[h9826790]

Hello everyone! I was doing an upgrade on my 2009 Mac Pro upgraded to 5,1 and noticed the North Bridge was wiggly, so I used some screws, sprints and nuts to re-secure it into place after getting rid of the regular Apple Northbridge holders. However, upon installing the new CPUs and booting - the GPU fans blast at full speed, I am greeted by a black screen and there is no chime. The CPUs I am using are Xeon x5670s.


Now, I noticed that if I only have CPU A installed, the system boots and works well, it is only upon installation of CPU B that this occurs. I’ve used both CPUs in socket A to verify that they are working, so I’m stumped as to what is causing this problem. The pins seem to be in great condition from what I can tell.


If anyone can shed some light on this it would be greatly appreciated!

Most like you can't get the tension right on heatsink B.

As long as you can boot with CPU A only. I don't think that's NB related (especially you can check the NB temperature after you boot with CPU A only).

 

[Jabaar]

Most like you can't get the tension right on heatsink B.

As long as you can boot with CPU A only. I don't think that's NB related (especially you can check the NB temperature after you boot with CPU A only).

The only thing throwing me off honestly is the fact that the Gt 120 I have temporarily in my system blows its fans at full speed, and there are no ram lights. I’ll likely keep trying to get the tension correct soon.

 

[MIKX]

Jabaar

I recommend this if you use the "Nut & Bolt" Northbridge heatsink technique.

======================================
Nut & Bolt Norhbridge technique ( of course, clean and reapply thermal paste. )

From the Northbridge heatsink top . .

1. M3 bolt ( from memory length 20mm ).
2. 1/2 of a ballpoint pen spring.
Northbridge heatsink top

Northbridge heatsink bottom
3. Non-conductive M3 washer
4. M3 Metal washer
5. M3 nut
6. M3 nut = to lock the upper M3 nut at about the same tension that the spring
of a plastic rivet would normally be set at.
( gently pull one of the OK rivets to get a 'feel' for getting similar "rivet spring tension" to allow for " expansion -contraction ". as the Northbridge heats up - especially in summer.)

 

[Jabaar]

Jabaar

I recommend this if you use the "Nut & Bolt" Northbridge heatsink technique.

======================================
Nut & Bolt Norhbridge technique ( of course, clean and reapply thermal paste. )

From the Northbridge heatsink top . .

1. M3 bolt ( from memory length 20mm ).
2. 1/2 of a ballpoint pen spring.
Northbridge heatsink top

Northbridge heatsink bottom
3. Non-conductive M3 washer
4. M3 Metal washer
5. M3 nut
6. M3 nut = to lock the upper M3 nut at about the same tension that the spring
of a plastic rivet would normally be set at.
( gently pull one of the OK rivets to get a 'feel' for getting similar "rivet spring tension" to allow for " expansion -contraction ". as the Northbridge heats up - especially in summer.)

Ended up cleaning everything and re seating the north bridge and still no luck, CPU A works like a charm, cpu B is being annoying and doesn’t seem to want to properly work. May play around with the pins and see if they may have gotten pushed down and I didn’t notice it.

 

[MIKX]

Don't give up. . write down how many turns you do for CPU B - a " little " tight seems to be OK.
Much easier on a 5,1. Tighten diagonally.

 

[Jabaar]

Don't give up. . write down how many turns you do for CPU B - a " little " tight seems to be OK.
Much easier on a 5,1. Tighten diagonally.

I’ll keep trying, I’ve done this upgrade plenty of times before and just when I think I have the right tightness and the NorthBridge is fine it all goes south, I shall keep persevering!

 

[Jabaar]

Alright little update - put in the original CPUs and still no luck, likely something to do with the socket, as the cpu light is on when I have cpu a installed and cpu b simply sitting in the socket. Will continue trying to figure it out, if anyone has suggestions feel free to drop them!

 

[Mic-M4c]

Hi all !
I changed my 2x processors Mac Pro 5.1 (mid 2012) from 2.40GHz to 3.46GHzand notice the Northbrige was wobbly because of the right broken black clip (the one under the processor cooling cage). I then replaced the processors with their respective heatsink and restarted the Mac. I've ever upgraded biprocessors with success and checked if every step was OK, and that was. Unfortunately, I didn't hear the "Bong" sound but the light of the Power Button was continue "ON". Do you think it's because of the wobbly Northbridge ?
I ordered the same white clips as : https://www.amazon.fr/gp/product/B08NCTSZ1Y/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Any advice, any help please ? Thank you in advance ??

 

[h9826790]

Hi all !
I changed my 2x processors Mac Pro 5.1 (mid 2012) from 2.40GHz to 3.46GHzand notice the Northbrige was wobbly because of the right broken black clip (the one under the processor cooling cage). I then replaced the processors with their respective heatsink and restarted the Mac. I've ever upgraded biprocessors with success and checked if every step was OK, and that was. Unfortunately, I didn't hear the "Bong" sound but the light of the Power Button was continue "ON". Do you think it's because of the wobbly Northbridge ?
I ordered the same white clips as : https://www.amazon.fr/gp/product/B08NCTSZ1Y/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Any advice, any help please ? Thank you in advance ??

There are more than one variables. It's hardware to tell which one is the problem.

Of course, you should fix the NB heatsink ASAP. However, as long as the heatsink is there. The cMP should able to POST (because the NB still cool at the first few seconds) after you just swap the CPU.

In your case, first check if there is any red light in the CPU tray (you can open the cMP side panel when it's powered on).

If no red light, then most likely at least one of the CPU not seated properly (yet), or at least one of the heatsink isn't tight enough.

For Mac Pro 2012, we usually just swap both CPU at the same time. But if you need to diagnose, you may only install CPU 1 into socket A (leave socket B open without the heatsink). The cMP should boot (with full fan speed. The fans are rated to do so, no need to worry about that, just a bit noisy).

And if CPU 1 can boot, then you can continue to install CPU 2 (or swap in CPU 2 into socket A, if you suspect the CPU itself is faulty).

If both CPU can't boot in socket A, then you should check if there is any bent pin in the socket.

 

[Mic-M4c]

There are more than one variables. It's hardware to tell which one is the problem.

Of course, you should fix the NB heatsink ASAP. However, as long as the heatsink is there. The cMP should able to POST (because the NB still cool at the first few seconds) after you just swap the CPU.

In your case, first check if there is any red light in the CPU tray (you can open the cMP side panel when it's powered on).

If no red light, then most likely at least one of the CPU not seated properly (yet), or at least one of the heatsink isn't tight enough.

For Mac Pro 2012, we usually just swap both CPU at the same time. But if you need to diagnose, you may only install CPU 1 into socket A (leave socket B open without the heatsink). The cMP should boot (with full fan speed. The fans are rated to do so, no need to worry about that, just a bit noisy).

And if CPU 1 can boot, then you can continue to install CPU 2 (or swap in CPU 2 into socket A, if you suspect the CPU itself is faulty).

If both CPU can't boot in socket A, then you should check if there is any bent pin in the socket.

Hello Martin ??
Thank you for tour advice. I've ordered white clip/rivet with an integrated spring on each. I watched a tutorial on YouTube to change my black broken clips (The Housse of Moth).
I soon as I've received them, I fix the Northbridge heatsink ans test again what you told me here.
I don't want to test before, it's too risky without the NB heatsink.
Thank you !

 

[Matty_TypeR]

I always use the Nut and bolt method, i use the springs from the original plastic clips, tighten down so the heatsink can move and the springs are even as they were under the plastic clip downs. just don't tighten down fully as you cant tell if heatsink is even across NB and risk damaging NB chip with to much pressure on one side.

The delta between NB diode is also variable, depending on where and how well the thermal temp sensor is glued to NB heatsink, I have seen people say a delta of 10 means good contact but have found this can change with different NB heatsinks depending on temp sensor mounting on said heat sink.

You can add extra cooling to the NB and ram using this method i did a few years ago. it works and keeps temps down nicely.

Some extra cooling makes a difference 5.1pro | MacRumors Forums

As for CPU mounting in a 4.1 dual CPU tray delided CPU's are better but can be done with out deliding the CPU useing a 1.5mm shim washer over mount posts, make sure its a shim washer not a stamped out washer from your DIY store. you can even mount them with no washers but if you over tighten the heatsinks you can damage the socket and pins.

If you find the red cpu light comes on its most likely to tight and pins are not touching CPU. if you look at the socket the cpu should touch the pins just by placing in socket as the CPU itself is against the plastic edge of the socket mount. over tightening the heatsinks pushes CPU hard against plastic edge of socket mount literally bending the CPU mount and board itself and as we know the traces from CPU are in the board and copper traces dont stretch inside the cpu board itself they break and render the board useless.

I would inspect the socket pins with a powerfull magnifying glass to see if there is any pins that are stuck down or bent. you can straighten the pins if your very careful useing a dentist pick tool. if you use alot of thermal paste when mounting as it squeezes out making the mounting screws become loser which can also give you a red CPU light. a light even spread of thermal paste is the way to go.

Mac pro 5.1 cpu tray is much easier to replace the CPU's because the heatsinks tighten fully after doing half a turn on each in a cross over pattern 1-3-4-2 and back again untill tight. you also have the CPU lock down tray around the socket. if the red CPU light comes on either CPU not mounted correctly or duff CPU but if proven working then socket pin damage or some times even CPU's mounted the wrong way round and clip forced down. even the back of the cpu might have debris or dirt on it, clean with alcohol before mounting cpu in socket making sure the CPU is placed straight down taking care it located in the right way round with the little notches in cpu lining up with the socket.


I hope you both have success with your CPU boards ?

 

[Mic-M4c]

Hi all !
Can I try to install CPU A only with its heatsink but without CPU B and its heatsink AND without the Northbridge heatsink for a minute only, simply to try if my Mac Pro Dual socket can boot and make the start chime ?

 

[Matty_TypeR]

You risk damaging the north-bridge chip having no heatsink on it, as boot time is when its very active. not worth the risk i would say.

 

[Mic-M4c]

OK then I wait for my plastic rivet clips with springs.??

 

[h9826790]

Hi all !
Can I try to install CPU A only with its heatsink but without CPU B and its heatsink AND without the Northbridge heatsink for a minute only, simply to try if my Mac Pro Dual socket can boot and make the start chime ?

You can use zip tie as temporary rivet, don't power up the computer without the NB heatsink. That thing can overheat in seconds without heatsink.

Or, at least use heatsink with thermal paste, just no rivet (the thermal paste should be sticky enough to hold the heatsink into position, but just not enough down pressure to improve cooling). That still much much better than nothing, and should be enough for just a few seconds POST test.

 

[Mic-M4c]

I will soon receive my rivets clips and will be back here to report my try to fix the NB heatsink.

 

[Mic-M4c]

I'm back here to say that I succeeded in replacing the Northbridge Heatsink black rivets by white ones !
The 2 processors are OK and the Mac Pro makes normally its "chime" ))
Thank you guys !

I followed the fantastic video tutorial of The House of Moth :

With theses white plastic rivets :

https://www.amazon.fr/gp/product/B08NCTSZ1Y/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

– The nasty old black destroyed rivets :

– The NB Heatsink on the left (be carreful not to damage the temperature black cable) :

– A quite thin layer of thermal paste :

– The new white rivets installed :