What are the applications and tools used by computer hardware servicing?

Answer 1

That greatly depends on your focus.

• End-user desktop repair typically focuses on replacement of whole parts such as a motherboard or hard drive. This type of repair typically only requires screwdrivers and context-based diagnosis, and the more advanced, flashy software or hardware diagnosis tools are either inaccurate or focus only on particular circumstances that your issue may or may not fall under. Other than a good SMART tool for hard drives and a RAM test program, software that attempts to diagnose problems typically can cause hardware failure on a damaged or poorly-designed computer, and should be used with caution.
• End-user mobile repair, laptop repair, and gaming console repair requires good jeweler's screwdrivers and security bits or pry tools, but otherwise nothing more than the desktops do. Diag tools, if available for the device you're working on, are again of little use unless the issue is clearly within their scope, and are almost certainly dangerous if they attempt to stress test any part of the system, as very few portable devices can tolerate full load for an extended period of time.
• Lastly, middle-vendor repair and manufacturing repair make use of soldering irons and multimeters to repair the circuit boards themselves. These forms of repair require a certain degree of knowledge of electronics, and technical documentation from the manufacturer is highly recommended. Many technicians at this level will often specialize in only one model or one type of product, and may also be required to reflash storage units attached to the boards if applicable. Reprogramming is typically done using a "sled" that makes contact in the correct places without requiring soldering. If you have access to the tools and documentation essentially required to repair at this level, you probably already know about it.