Fairly easy to fix these days.
Most repair is a matter of finding the malfunctioning part and replacing it. Soldering and board-level repair are rare.
Caveats:
- If your computer is under warranty, don’t open to the computer and void your warranty. Have it repaired at a designated facility.
- Before you open up a computer, turn off the power switch and remove the AC plug (otherwise there may still be power inside the chassis). For laptops, remove the battery. If you are going to be working around the power supply, you probably should discharge internal components by pressing the power button for 30 seconds or more.
- If you are going to be handling components, be aware of ESD precautions. Service people aren’t agreed on how important ESD precautions are, but they don’t hurt.
- If you are uncomfortable with opening up a computer, don’t do it.