Soltek Qbic External Power Supply Fan Mod Detailed Description

So, imagine my surprise to find that the little photo I put on my site about an external power supply fan for my QBIC would get a few hundred hits in a week. I guess there's some interest in it, so with that, here is a fuller description of the project.

Now that Soltek spare parts are going to be even harder to get than before, it occured to me that perhaps I should be a little less cavalier about how hot my powersupply gets. My 3401 is on 24/7 (has been for more than a year), and is also my primary gaming rig (I also bring it to LAN parties and Gaming Conventions). Normally, the air coming out of the power supply is very VERY warm (if not HOT), and the top of the case above the power supply is very VERY warm, and the back of the power supply itself is, well, I would say HOT. The problem is airflow; air barely blows out the back of the power supply at all, despite an interal 80mm power supply fan.

I'm sure the fact that the CPU cooler and the Power Supply fan are sucking air in opposite directions from the same little area inside the case doesn't help matters much. I'm rather considering getting an XP-90 CPU cooler and a 92mm Nexus fan sucking up, thereby blowing air into the power supply, and hopefully helping the power supply get some warm air out.

But first, I remembered this post, and I have plenty of spare 80mm case fans laying around, so I thought I would see what happened if I tried it myself. CompUSA has 60mm-to-80mm fan adapters for $4, so I picked one up at lunch. With just a little reaming of the soft plastic holes on the 60mm side of the adapter, it fits perfectly into the two screw holes for the screws that hold the power suppy to the chassis. I had longer-than-average case screws in my parts bin. So, the adapter screwed on with just two screws to the Qbic, which seems fine.

I didn't bother the to chop up the power supply grating. I want this mod to be reversable.

The 80mm fan I have is a Vantec adjustable fan; it has its own speed knob, so I cranked it down to its slowest, quietest setting. I can't hear it under my desk, but I can when I bend down and listen for it. If I stick with this mod, I'll purchase a super-quiet fan. Screwing the fan to the adapter is practically impossible when the adapter is installed, so the fan is attached with Zip ties.

And finally, the power leads for the fan pass through the IcyQ vent slots on the back of the system to a molex 3-to-4 pin adapter.

And as for the cooling results: they are excellent. We're talking about 6C degrees cooler in the case and 4C for the hard drive, but more importantly, the top of the case above the power supply isn't even warm, and the air moving through the PS isn't hot as before; now it is just slightly warm, even during intense gaming or ripping. I'm pretty confident this should extend the life of the power supply by quite a bit too.

Additionally, for the first time ever, the interal case temp is actually lower than the hard drive temp.

The only real problem with this mod is that it looks just terrible; totally ghetto. It also makes transporting my portable SFF machine problematic, since I can't lie it on its back in its knapsack. I could stand it on its front, which may scratch things up, or I could move on to Phase Two...

Phase Two would be to have the fan (either an 80mm adapted, or a 60mm fan) mounted to the back of the case with some sort of quick-release mechanism, or perhaps Velcro. "But what about the power connector?" you ask? Well, why should it be internally powered? With a generic AC to DC Adapter, I could just run the fan from an external AC outlet on my power strip. If I used an adapter with different output voltages, I could even change the fan's speed by changing the electrical current it got. Then when it came time to move the computer, I could unplug the fan, take it off the computer, and then toss it into my computer bag.

Phase Two will probably take place over Christmas, 2005. Stay tuned for further developments... Leave comments too.