Motherboard northbridge reaches 120c (!) and dies

[wumpus]

wumpus, did you check what kind thermal paste there was under northbridge heatsink when changing it?

Yep, if you read through, you'll see that I cleaned and used Ceramique. So all these temps are with *good* heatsink contact. I highly recommend cleaning the heatsinks on the P5B -- the existing thermal pads are crap, and mine were only making partial contact anyway.

a good idea to stick the squirrel cage fan onto the VRM heatsink, even though it says not to unless using a passive heatsink or watercooling

But the VRM heatsink never gets all that warm. At least mine never did. The actual heatsink would be pushing 80c and the VRM heatsink, which is connected by a heatpipe to the heatsink, was relatively cool to the touch. Hmm. I wonder if the heatpipe is just plain defective.

It's funny because the items the VRM heatsink is touching-- the small black thingies by the cpu socket*-- do not get all that hot. It's the much larger black square thingies* nearby that get hot. I put some Iceberq VGA copper heatsinks on those.

* pardon my ignorance..

[jaganath]

It's the much larger black square thingies* nearby that get hot.

These are power MOSFETs I would imagine.

[cmthomson]

It's funny because the items the VRM heatsink is touching-- the small black thingies by the cpu socket*-- do not get all that hot. It's the much larger black square thingies* nearby that get hot. I put some Iceberq VGA copper heatsinks on those.

* pardon my ignorance..

The small thingies the heat sink touches are the MOSFETs. On this board, they don't get very hot because it is an 8-phase design, much more efficient than a cheaper motherboard.

The large thingies (the ones marked RIO) are passive inductors. They don't need cooling, as they're constructed entirely from plastic, copper and ferrite.

[Operandi]

Note that the case was open at the time, so airflow was not an issue. I took out my temperature gun and checked the

i would say that sometimes an open case spells less cooling because fan airflow just goes straight out of the case rather then pass over hot components.

regards,

I realize it's a bit late in the game but I think kentc has a pretty good point here. It's been my experience that all passively cooled components run cooler with the case closed, sometimes significantly so. This applies to VGA cards as well as northbridges and chipsets.

[zjohnr]

Excerpt below is from page 2 of the Oct 10'th Tom's Hardware article, Cheap Thrills: Core 2 Duo E6400 Overclocked to 3.33 GHz.

Our final [HSF] candidate for "insane clock speeds within rational budgets" is Gigabyte's new 3D Galaxy II. What may at first appear to be a superfluous feature, a fan over the CPU water block serves the practical purpose of cooling voltage regulator components surrounding the CPU socket.

The observation about including a fan to cool components near the CPU on the MB seems to fit in well with the rest of this thread, no?

-john

[tonalt]

Very beautiful picture, like a futuristic town from science fiction movies. Zalman ZM-NBF47 was also a tight fit between SLI-slots with Asus A8N-SLI.

[Jodiuh]

What did pc probe say for MB temp? I've got 38C on mine after cleaning the goo.

It's still very hot to the touch tho. I've a Jing Ting, but I'm not sure if it'll fit w/ the Tuniq. I think a TRight 05 or 05 sli would do it tho.

[Willy Higinbotham]

Sorry for bumping an old thread, but it had to be done.

wumpus, I'm planning to buy exactly the same NB cooler, but according to the Thermalright website, the cooler is not compatible with P5B Deluxe. So, I'm not sure whether I should order it or not.

So, how did you manage to install it? Did you have to do any modifying?

Also, looking at your photos, it looks like a tight fit indeed. I hope that it will fit next to the Thermalright Ultra-120 as well.

Thanks.

[aristide1]

The whole cooling design is dumb. The VRM can withstand much higher temperatures than the northbridge. There is no reason to tie them together thermally......

Otherwise, it would make sense to re-engineer the cooling system with a Zalman on the northbridge, and some simple extruded heatsinks on the VRM.

You summized why I chose the Asus P5B-E and not the Deluxe. As I head towards a 400 MHz FSB I will let you know what the outcome will be. But right now I am looking at the ThermalRight NB cooler and some separate MOSFET heatsinks as feasible.

[mikearthur]

Hey wumpus, I've had almost an identical problem with almost identical hardware.

I also have a C2D, the Scythe Infinity and a P5B-Deluxe/Wifi.

Was playing Oblivion happily on a overclock of a E6320 to 3.01Ghz without needing to adjust the core voltage, memory or northbridge and getting rock-hard stability on Prime95 and Memtest86+.

System beeped and then shut down playing Oblivion and the northbridge was far too hot to touch.

I suspect its a combination of the poor thermal pasting and our Infinities causing the heatsink to not get the airflow it needs. The poor thing is that this motherboard is listed as "supported" on the Infinity's webpage

Getting the board RMAd so should get picked up tomorrow and a new one dispatched soon. Does the overclocking actually put much stress on the northbridge? Am I worth just repasting or do you think I need another heatsink?

Thanks!

[aristide1]

Getting the board RMAd so should get picked up tomorrow and a new one dispatched soon. Does the overclocking actually put much stress on the northbridge? Am I worth just repasting or do you think I need another heatsink?Thanks!

Yes more speed and voltage will heat up your NB so if you RMA the board you won't neccessarily gain anything.

For all the talk about thermal characteristics of cpus the NB seems to be quite neglected and quite inefficient, just based on the amount of heat of it produces, or at best, not nearly adequately designed enough.

[Matija]

This thread got me worried...

I have the P5B Deluxe and an E4300 at 2.4GHz (still with a stock Intel cooler). No idea about how the northbridge is doing, but the computer is stable even when under heavy load for a couple of hours.

I think I can get a non-revB Ninja, or a Noctua (which I like more). But then I'm risking the same problems as mentioned here. Even worse, I was thinking of getting a HR-03 for my X1950Pro and mounting it so that it's on top of the card. That would be extra heat in that area, and the northbridge might not like it, even though it's not overclocked much.

Do you think it might be a good idea to get the HR-05 (SLI?) as well?

[ronrem]

These heatpipe chipset coolers rely on airflow at the heat exchanger/fins and with an open case that may not be happening.

HOT RODDING a computer is like hot rodding a car. Stuff that's fine at 200 hp may not hold up to 450 hp. In this case---there's the heat exchanger not getting airflow-a low efficiency thermal pad---excessive overvolt....3 heat makers going with a "Burn-In" app. Result should have been anticipated,as the smell test tends to give warning when the damage is done.

There's a LOT of mobos and a lot of variables with each. I always read all the Newegg user reviews just to see what the "issues" are-and every board has SOME quirks. Even if 80% of the reviews tell you nothing-it's the few that say something Review sites miss in a one-time review that's the gold. Often the best boards get 50-200 reviews-which is quite a cross section.
I'd seen it mentioned that some chipset coolers tended to be loose or use poor grease/pads.