best/worst practice on reverse engineering a circuit/gear

[Martin Miranda]

 

i have been repairing vintage gear and reverse engineering is one of my hobby/past time. (well.. a schematic/service manual helps) but why take the fun out of repairing your own gear?

is there a tool that automates this?  or the sheer collective engineers on forum is better? 

[jwet]

There is great British YouTuber named BIGCLIVEDOTCOM that does a lot of reverse engineering of PCB type gear, might be applicable to some of your work and might give you some ideas even on the real vintage stuff.  He takes high resolution pictures, reverses them with PC software, prints them out and uses transparency foil stock, makers, etc to make the process easier.  Worth a watch.

In my experience, I go through with a continuity beeper/DMM and draw the circuit as I go.  I then try to redraw the circuit a couple of times until it makes sense.  Usually, the first stab makes everything look complicated and upside down- like a bad schematic.  After you revise it a couple of times, you'll recognize structures and the flow of the circuit.  Bypassing and similar circuits can make for head scratchers.  I try to follow the real signal stuff and do the supply rails and don't worry if its not all perfect.  If you can power it up safely, you can refine your schematic with DC bias levels, etc. and chase out the bypass and bias circuits.

Good luck.