My Computer and I: Rat-a-tat-a-tat

My desktop is a 3-year-old Dell Dimension 8400. It was high-end at the time it was bought, but regardless is starting to show its age. I have upgraded some of its parts since then to keep playing World of Warcraft bearable, but of course it will need to be replaced eventually.

I have had my share of computer problems with my current computer (not suggesting that Dell is necessarily a poor computer assembler, mind you). Other than high school computing studies, I have had no formal training in maintaining a computer, so I usually need to end up experimenting when something goes wrong. Without further ado...

The Problem:
I had upgraded the video card (to an NVIDIA GeForce 8400 GS). After its installation, the computer tower would emit a noticeable low-pitch rattling sound. It was easily recognised as percussion and distinct from beeps emitted from the system speaker.

A computer fan.

Background Information:

• Percussion can only be produced by moving parts. The only moving parts in a computer tower are the fans and the shaft and heads of magnetic hard drives, optical disc drives and floppy disk drives.
• A noticeable sound is produced when an object hits the blades of a fan.
• Like all mechanical machinery, fans suffer from wear due to friction around the rotating shaft. This area is the source of most of a fan's noise and vibrations (which in turn can cause the rest of the fan's body to emit noise).

The Circumstances:

• My computer has all of the above moving parts, of which the fans are the power supply, CPU and video card fans. The sound would persist with no media loaded into the optical disc and floppy disk drives.
• The computer's performance was initially unaffected.

The first computer log entry documenting a literal bug being found inside a computer.

The Experience:

• I could immediately eliminate the optical disc and floppy disk drives as the source of the sound.
• I did not think a failing hard drive could emit as audible a sound and yet still not have its performance adversely impacted, and accordingly eliminated it as the source.
• I initially worried that, by opening the computer case to install the video card, I introduced a foreign object into one of the larger fans. While highly advised against, knocking the computer tower would remove the sound temporarily. This was evidence in support of a foreign object in a fan, and did not test it any further by inspecting the fans directly.
• In one occasion, the sound ceased while World of Warcraft was running. After a few minutes, the framerate slowed to near 4 FPS. This was overwhelming evidence in support of a faulty video card fan (where overheating would cause the video card to slow its processing). It was still under warranty, so I exchanged the video card for another of the same model and installed it. The rattling sound ceased permanently!

Implications:

• It was the video card fan that was causing the sound! It would make said noise when spinning and only cease to make noise when physical shock dislodged it and stopped spinning as a result.
• Upon close inspection, the fan turned out to be loosely attached to its cage.
• Warranty is your friend. It also benefits the manufacturer by not needing to spend excessively on perfecting the production process; it is more economical simply to replace faulty products.