PC Meltdown

The good – Disaster averted

The bad – Relying on cheap fans to cool PC components

The ugly – I feared the worst


I had two fans fail, virtually simultaneously (I believe), in my Windows PC. One was the primary (rear) case fan, an Antec TriCool 120mm. The other was the cheap manufacturer-installed 40mm fan designed to cool the Northbridge chip on my MSI K8N Neo4 Platinum/SLI motherboard. Both fans had been performing without issue since I built this PC in 2005.

Instant failure without warning
I don’t know exactly when these fans actually quit functioning. My first, and only, warning was noise coming from the PC. I traced it to the primary case fan, and noticed that it was not running at its normal constant speed. I then looked at the temperature readings provided by sensors built into the PC’s components, and two others provided with the PC case, an Antec P160. I saw the temperatures rising and immediately tried to save the data file I was working on, before shutting down the PC, but the system shut itself down before I could do so.

Initial inspection
When I looked inside the PC, I discovered that the primary case fan was indeed broken. The fan blade assembly connecting shaft had snapped. I temporarily replaced this fan with one that came with the Antec P160 case. I tried to reboot the PC, but it wouldn’t power up. I immediately feared the worst. Had the temperatures risen high enough to cause fatal damage to one or more major components of this PC?

Upon further inspection
I then looked for other signs of damage inside the PC. The cooling fan for the CPU (an AMD Athlon 64 3200+ “Venice”) appeared to be intact. The fan blades rotated freely without signs of damage. Same for the cooling fan on my video card (a BFG GeForce 6800 GT OC), and both fans in my power supply (an OCZ PowerStream 520W). Then I spotted the damaged Northbridge chip cooling fan installed on the motherboard. It was askew and seized.

A terminal meltdown?
I was now VERY concerned that the Northbridge chip had fried, which would require replacement of the motherboard. Frankly, this was an expense I couldn’t afford at the moment. Perhaps, if I was lucky, the fail-safe provisions of the motherboard’s BIOS had kicked into action and shut the system down BEFORE any fatal damage had taken place. I had my fingers crossed.

A faulty design
Do a web search about Northbridge cooling fans and you will quickly discover that this design is flawed—the fans are cheap, noisy, ineffective, and prone to failure. This is not just true for motherboards manufactured by MSI, but for every manufacturer that uses these cheap little 40mm fans to cool the Northbridge chip.

Other options
There are several aftermarket fan replacement options, but most either still use a cheap 40mm fan (with the same issues previously mentioned), or are so large that they can’t be installed without modification, or perhaps can’t be installed at all, because of interference with installed components (video or other PCI cards, etc.).

A potential solution
I found one aftermarket solution, the Zalman ZM-NB47J Northbridge heat sink, which is designed to cool the Northbridge chip WITHOUT using a fan. Searching various computer hardware forums, I read several posts by people who had installed these successfully on the same MSI motherboard used in my PC system. Most of them had to trim a few heat sink risers (columns) to clear their video cards, but reported that the modification was relatively easy, and the final result was effective in cooling the Northbridge chip. I decided that I would give this a try.

Ordering parts
I read many user reviews about the Antec TriCool 120mm case fan, and didn’t read about a single failure. Perhaps my failure was an aberration. I like the fan’s specifications and features, compared to others that are readily available, so I decided to try another one. I ordered the Antec TriCool 120mm case fan and the Zalman ZM-NB47J Northbridge heat sink. They arrived promptly, but I waited a while before installing them.

Fear and apprehension
To be honest, I still had this fear in the back of my mind that the overheating situation had possibly caused fatal damage to a major component that I couldn’t afford to replace right now. So I did what I seem to do best in situations surrounded with uncertainty: I procrastinated. Oh, I immediately disassembled the PC, removing ALL components from the case, cleaning them AND the case. I even (eventually) got around to modifying the Zalman ZM-NB47J Northbridge heat sink—I had to remove one row of risers (columns) because of interference with my video card. Everything was ready for reassembly, but I waited, and waited, and waited…

A breakthrough
Finally, I had the motivation I needed to proceed. I wanted to use a virtual musical instrument software application—Native Instruments’ Akoustik Piano (sampled acoustic piano)—on some classical solo piano music I’m recording. (My Pro Tools rig is installed on one of my Macs, but I use this PC to run all of my Native Instruments software.)

Believe me, this is REALLY BIG motivation! So I installed the Zalman ZM-NB47J Northbridge heat sink on the motherboard and reassembled everything. This time, I installed a second 120mm case fan (the one that came with my PC case) in the front of my PC case. It pulls air into the case and blows it over my two hard drives, the Zalman ZM-NB47J Northbridge heat sink, and my video card, which should help cool these items.

I made the necessary connections (video monitor, ethernet, etc.), plugged in the power cord, crossed my fingers, and turned on the PC. The system booted right up! All of my hardware and software worked perfectly, just as it had before the PC had shut itself down. I breathed a BIG sigh of relief. I had averted a disastrous meltdown. The fail-safe features of the BIOS saved my PC.

An improvement
My PC now runs cooler than before. The front case fan runs at 1,600 RPM and blows air in at 56 CFM, while the rear case fan is running at 2,000 RPM and is exhausting air at 79 CFM, if you believe the manufacturer’s specifications.

A happy ending
I am now happily recording beautiful Chopin piano pieces, using the wonderful-sounding Steinway D Concert Grand piano in NI’s Akoustik Piano. Life is good!

Update June 3, 2013
The Zalman ZM-NB47J Northbridge heat sink is working as expected. I would highly recommend this upgrade to anyone who has problems with the cheap manufacturer-installed 40mm fan on their motherboards.

So far the case fans are working without issues. All is (relatively) quiet and cool.


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