It is recommended to be an apprentice in a maintenance company. As long as you know electronic technology, you can still learn it. You can buy a book to help you learn the theoretical principles.
If you don't understand electronic technology, it is still difficult to learn, but it is not impossible to learn. You can buy a book to help you learn electronic technology.
Apprentice, while learning the principle, you should have a better brain, be diligent and learn quickly.
This job requires high technology, and the most basic requirement is chip-level maintenance, without drawings.
In this line of work, all are industrial maintenance boards, even boards that many maintenance engineers have never seen.