Its been a struggle for the poorly trained and lazy person in the automotive field for the last 25 years. Cars have gotten a lot more reliable right off the showroom floor, reducing work. The problems they do have require electronics and in-depth technical knowledge to fix (the willingness to read!).
Whats a waste-of-space lowly paid person to do? Well, you sometimes you cheat.
A relative took their desktop computer in to Best-Buy about 10 years ago. The only reason the did so is because they had a warranty on the unit (not sure who purchased it). The "Geek Squad" was on the job! Based on the symptoms they described to me, the hard the power supply or maybe a cable had some loose. The Squad reported she needed a new hard drive, data recovery services, and windows loading fee. Something like 600$, but the warranty would cover the hard drive, so about 450$ out of pocket. Balking at this she walk out, eventually bringing the unit to me. Long story short, the hard drive power connector was not even plugged in. In fact, it was suspiciously well secured to the chassis. 30 second fix. Now, did the squad intentionally remove the plug? Good question.