Why is my Northbridge Chip running at dangerously high temperatures?

Thanks for the reply. 🙂

I'm going to see if I can swap the screw currently holding it down to the other side (since the cpu heatsink pushes down on it from the other side) and reapplying some arctic silver.

If that doesn't work... I guess it's time for a new processor board.

How much did this cost you at the Apple Store? I can see them online for ~$369. If it's less than that, I'll take it in if the screw thing doesn't work.

Thanks!

FYI - I had the exact same problem as Chris. Same thing became loose which I noticed after removing the CPU and heatsink.

Unsure if I reinstalled the CPU incorrectly, but I couldn't boot up after I put the CPU heat sink back on. I had no choice but to follow suit and get my processor board replaced.

Almost lost a RAID 0, so make sure you backup your data before poking around your Northbridge heatsink.

On a side note, this seems to be way too common of a problem. What gives?

I'm wondering if anyone was able to find a solution beyond buying a new procesor board (talk about overkill!)

I was thinking of possibly using a nut and bolt. I'm worried that a metal nut&bolt combo could cause a short on the processor board. There might be a reason apple used cheap platic clips. but what if i used a nylon washer on teh processor board side?

Or what if i tried to find a plastic nut & bolt combo that would fit?

For what it's worth, buying the new processor board fixed the problem for me entirely.

My Wifi was giving me problems before too, and now it's operating fine.

i'd like to exhaust other possibilites before buying an entire processor board because of a sigle clip. besides the TNOD error i get from the ASD diagnostic everything else seems fine with the machine.

Hi all,

I don't know if anyone is still interested since a year passed, but still...

I had the same problem as Chris and I didn't want to buy a new board for a tiny plastic pin.

Seemed logical to replace the pin with a screw, which is what I did.

It helped for a while, then the problem became much fierce and I reached Chris's temperatures.

After opening my Mac again, I found out the other pin broke as well.

So, I replaced it with a screw also.

I also cleaned everything from dust, put some new thermal paste and now my northbridge chip runs at 76 C and It's now a humid hot summer night (I didn't turn the air conditioning on).

I guess this is a decent temperature for the northbridge chip at these conditions.

I know it's NOT what one is supposed to do buy the book, but I figure I'll always be able to replace the whole board if needed.

In my opinion, this is the cheapest decent fix for this problem.

It only cost me 2 screws and 2 bolts I had laying around.

dunno, maybe try here...

http://heatsinkfactory.com/retention-hardware.html

if you take a photo of the one that isn't broke, try your local PC repair place??

sorry, I got nothing

JB

Well I don't know if anyone is still following but add me to the list of users that has experienced this problem with an early 2009 mac pro, quad core. In my case, my machine simply shut down one night while I was asleep - graphics card fan running at full throttle when I tried to boot the next day. It didn't take me long to find the problem thanks to this and some similar threads - and the rattle that I heard when I pulled out the processor tray to find the little black plastic screw and spring roll our from under the CPU's big heat sink. I never noticed a problem with the machine prior, although I hadn't checked Northbridge temps in a very long time.

I found a decent nylon screw and nut that will fit, and since I still have the spring and some arctic silver compound I'm hopeful that when I reattach tonight, the machine will boot. I have been told many systems have an electrical continuity check so that if the heatsink is not contacting on both sides of the chipset then there is a failsafe, although experiences here seem to suggest otherwise. My hope of course is that the machine shut down because the sink popped off and not because it has been off and my chipset is finally fried.

For what it's worth, no one at Apple - including the "genius?? bar" at 3 stores in my area was able to help me, or would even entertain the idea that I might know what is wrong with my own machine. Even with the broken clip in my hand I was asked if I was sure that a recent system software update might not be the problem. Ugh.

I'm going to try to reattach the sink with compound, re-compound the cpu and reattach its heatsink too, which I had to take off to get at the northbridge. Hopefully this works and I don't need a new processor board.

It seems to me that this is too common an issue. I plastic piece worth 30 cents may end up costing me $400. I have written to Apple but am not hopeful of a reply.

I had the same issue, heat sink spring loaded rivet broke. Northbridge temp rises to 127C, then crash.

Similar fixes to the above. 3mm hex long handled driver to remove the processor heatsinks. Cleaned off the dried compound, applied new compound. I used two #6 1/2" wood screws to reattach the heatsink. But I took the springs from the plastic rivets, and put them on the screws to allow a little finessing the pressure.

It was a little fiddly to get the screws in, needed to apply a little pressure while turning, and keep the heatsink flat. But once on it seems solid. Temp is now stable at 102°C, which still seems high, but it isn't crashing.

I too suffered an overheating Northbridge chip in my Mac Pro (Early 2009). iStat was reporting a high of 128°C so I downloaded Macs Fan Control, which reported the same, and boosted the intake and exhaust fans to 1900 RPM, which brought the temperature down to about 115°C. Increasing the fan speed further just increased the noise and did nothing for the temperature. I read up on this site and others and after sifting the information, resolved the Northbridge issue. How I did it can be read here:

https://www.scribd.com/doc/269177794/How-I-Repaired-My-Northbridge