So what I am seeing here is that dive shop guys just do not know what they are doing, it is all a money scam, no one does it like I do it, etc, etc etc....
On behalf of the entire dive industry - I apologize if you have had a bad experience inside of a dive shop at some point in your life.
Again,
If you want to service your own set, then more power to you (insert slow clap here). I think it is very unfair to classify all of the dive shop technicians as being bad at their jobs. I would venture to say that if all of us knew absolutely nothing then there would be a few more deaths and incidents caused by gear malfunction. Regarding every regulator being same, it is true that some of the 1st stage systems are similar. There are pistons out there as well and the second stages can vary widely. Most important - please understand your set before taking it apart.
I know that I am not the best technician in the world, and do not claim / want to be. The minute I think I am, I will stop caring and then bad things happen. What I find most interesting is that certain people speak ill of dive shops, can fix any problem, blame manufacturers for defective gear and then seem to be surprised when no one wants to help them out because no matter what they do, they will have made a mistake somehow. In the words of Sweet Brown, "aint no body got time for that"
https://www.youtube.com/watch?v=bFEoMO0pc7k