Do electronics companies publish the diagram of their electric boards

Question

I'm new to the electronics world, and I came to know that electronics companies (As Fairchild) provide datasheet for the components they produce (As IGBT, Triac, etc.).

Do electronics companies (As Samsung, LG, Sony, etc.) provide a datasheets & a diagrams for the electric boards in their devices?

If the answer is NO! Then how can you tell what component is connected to other components in an electric board that you are fixing for a better diagnosis of the problem, especially with the existence of the "Surface" components as (Capacitors, Resistance, Optocoupler, etc.)?

If the answer is YES! Where can I find these diagrams?

Thank you in advance

Answer 1

If the manufacturer provides a service manual, it would be there. In the very old days it was common to have the schematics inside the manual or sometimes even glued to the inside of the case on old television sets, but those days are long gone. For test and lab equipment sometimes the schematics are provided with the detailed user manual.

Most consumer products are very reliable and not easy to fix so it makes little sense to make schematics available to to the public.

Sometimes 3rd parties like Sam's will provide service manuals.

Even without service manuals, looking for power supply problems and obvious connections between subsystems, backlight inverters and so on can allow a substantial subset of common issues to be repaired.

Answer 2

It's hard to believe all circuits are public. Maybe here and there you can find some. They used to be maybe 40 years ago, I saw once schemes of tv sets- for technicians who were able to fix them, which is a sort of a lost skill.

But the question is, why would you need it. Obviously not to fix. If you need a reference design, there is plenty of material available, for more or less anything.