Complete silence. No fan sounds. No grinding. Worst case scenario: it's the CPU fan gone bad, and every second you use your computer you are burning up the CPU chip. Most computers today are designed to turn themselves off once the temperature on the CPU reaches a certain level ... before damage takes place. However, this safety feature doesn't always prevent damage from occurring. After you get the fan fixed, you can experience random shut-downs and system errors that are directly related to a previous overheating incident. So, it is best not to run your computer at all during times when overheating may be an issue.

So the bottom line? Get to know your computer! Some noise is normal ... but excessive noise from any component on the computer usually indicates excessive wear and tear, not to mention possible emminent failure. So be alert and aware of what your computer sounds like now, ... before it has any problems.