What causes Northbridge chips to overheat?

[jacobean]

On desktop P4 computers aged anywhere from 2-5 years old. I've opened up the case to find the motherboad in perfect conditon, free of dust etc but the mini-heatsink on the board (Northbridge chip I think?) would be extremely hot.

The systems would freeze continually because of this.

What causes these "mini-heatsinks" to malfunction and is there any solution?

[370forlife]

Re: What causes Northbridge chips to overheat?

They need a fan.

[jacobean]

Re: What causes Northbridge chips to overheat?

ok thanks for suggestion but what is the root cause of problem?

[i4004]

Re: What causes Northbridge chips to overheat?

you should of looked at the psus of those machines...you would probably find crappy supply which causes high ripple, and that causes more heat...

[jacobean]

Re: What causes Northbridge chips to overheat?

Thanks i4004.

But what is the root-cause of this problem?

[kc8adu]

Re: What causes Northbridge chips to overheat?

many board mfrs. ASSume that airflow from the hsf will cool the nb.
often its just a bad design.

[stevo1210]

Re: What causes Northbridge chips to overheat?

Usually I think that the main idea of that Northbridge heatsink is to be passively cooled by the CPU can blowing onto it, but in some cases that doesn't go very well. Though I do suggest you check the PSU in case of ripple and voltage fluctuations. Now if that doesn't help then get a fan for the NB chipset heatsink.

[i4004]

Re: What causes Northbridge chips to overheat?

>But what is the root-cause of this problem?

well, THAT is the root cause if you had cool heatsink when machine was bought, and then hot after 2-5 years...

then again you probably don't know what was it like when new etc.

also, i dunno how is northbridge supplied; if it's supplied in a same way as cpu, then badcaps on mobo can cause this overheating and all other sorts of problems...

another thing to mention is what kc says; bad design...smetimes they just put too small heatsink on the chip...AND yet another thing is that some chips just get warmer than others...

to solve the issue i would first check psu, then caps on mobo(even if they're not bulging) and then put small fan on chipset sink if the psu and caps are ok...

[acstech]

Re: What causes Northbridge chips to overheat?

KC8 is right. Often times it's just bad design. I ran into this many times with Nforce 4 / 570 Asus boards. Often they'll design them so they can use the smallest heatsink possible where it will still function. Problem is, that heat degrades IC's. A temperature that may have worked when it was new may no longer work. The process is called degradation, and it happens to all IC's. It is accelerated by increased voltage (ripple being transient, usually high, voltage) and temperature.

You fix this problem in two ways. First, put a bigger heatsink on it, possibly with a fan. That alone might correct the problem. Second, as said above, look at your motherboard caps, specifically around the northbridge chip. If they're a bad brand (see bad caps list) they're suspect. Third, check the caps in your PSU.

If you're really ambitious, you can check ripple directly with an oscilliscope.

Good luck!

[NxB]

Re: What causes Northbridge chips to overheat?

Nobody has mentioned how most of the heat sinks are attached with crappy sticky tape. After 2 - 5 years i doubt it works well. Pulling it off and applying the thermal grease can damage the bga connection. I've done that (successfully) AND put fans on them before. I think in the scheme of things its planned obsolescence.

[i4004]

Re: What causes Northbridge chips to overheat?

>The process is called degradation

http://en.wikipedia.org/wiki/Electromigration
?

[acstech]

Re: What causes Northbridge chips to overheat?

I've heard both. Yes, that is the more correct term in this case.

[Wizard]

Re: What causes Northbridge chips to overheat?

1. On the northbridges using plastic BGA package with or without round thermal contact molded into it, I often find no heatsink paste or using non-thermal double sided stickers. (Most common on cheap generic boards including MSI and VIA chipset based boards).

2. The design of heatsink do matter. Where does air is blown towards? Retail intel heatsink for P4 and L775 blows air in all directions works very well. The ones that only blows in two directions that is not directed at chipsets is a issue.

Since when Intel and AMD now have cool running CPUs, I'm using their retail heatsinks and been buying up retail copper core heatsinks that was used on high watt CPUs on other CPUs too with slower fan speed.

Cheers, Wizard

[bgavin]

Re: What causes Northbridge chips to overheat?

Side draft coolers are another problem source.
The original VRM was designed for down draft cooling.

I use the Rocket V Cooler in my machines.
It is cheap, runs quietly, and offers excellent cooling for NB and passive video cards.