Who makes great troubleshooting flowcharts and repair manuals?

[Tectonic]

In your experience, who makes the best repair manuals and troubleshooting flowcharts? What makes them better than the rest?

I've been tasked to write troubleshooting and repair instructions. I wouldn't mind looking at a few great examples for inspiration.

cheers!

[G0HZU]

The faultfinding flowcharts in the Advantest TR4172 spectrum analyser service manual take some beating for thoroughness

There's nearly 90 different (cross referencing) flowcharts to navigate along if the analyser develops a fault. It also has various test routines in its program memory that can be accessed using special combinations of front panel key presses and it can self test its own synthesised LO and give a frequency readout for each LO on the CRT display when in faultfinding mode. These keypress routines are given in the flowcharts as you progress through them. At the end of each branch of the complex flowcharts there is usually a component identified as the faulty part.

I've never seen anything else like it and it puts HP/Agilent to shame but then this TR4172 analyser cost a lot more money and is far better built and far more capable than the equivalent flagship HP spectrum analyser from the 1980s. Awesome engineering from Japan

[Tectonic]

I've had a look at the manual for the TR4172 and it is quite impressive. What about their more modern equipment, did they improve in the last 32 years?