"Trouble-Shooting" is the term used by "computer geeks" for determining the causes of problems in your computer, and often includes repairing the PC or computer.
Trouble-shooting most often is just an attempt to make a PC or computer work in response to an irate user's call. In essence, trouble-shooting may be loading a piece of software, or replacing a whole hardware sub-system.
Let's look at some of the items you may have to troubleshoot, and some tools you will need to trouble-shoot, and possibly, replace a component.