Sometimes I am accused of being too laid back about life and problems. I take that as a compliment and consider my low key approach to life to be an asset not a liability. When it comes to computers, many computer users should also take a low key approach to many hardware problems.
Keyboards and Mice
If you start having a problem with a mouse or keyboard, the first thing to try is shutting the computer off, unplug and re-plug cables, then try again. If they still give you problems, go out and buy a new one. Mice and keyboards can't and shouldn't be repaired…just replace them. Mice and keyboards both can be found for less than $20. If your mouse or keyboard is a cordless one, always check the batteries.
Monitor prices have plummeted over the past five or so years. Repairing a monitor is a costly and often futile experience. If you start having monitor problems, check your monitor with a neighbor's or family members computer. If it still doesn't work, replace it. If it DOES work on a different computer, your computer has a different problem and should be checked out by a professional. When shopping for a monitor, you don't have to buy the same brand you are replacing. All monitors will work any computer…with very few exceptions.
CD/DVD and CD/DVD Burner drives
Probably the most commonly replaced item in a computer, don't bother fussing with these items and losing sleep. If they stop working, pull them out and replace them with a new one. Cost is less than $50 and can be done by anyone comfortable with a screwdriver.
These are probably the most common and easiest to solve hardware problems. Don't sweat these items when something goes wacky, just replace them and you will save a lot of time, frustration, and probably money too.