I have had a quick search around here and I did not find a link to this great resource. (sorry if it has been previously shared!)
Description taken from website:
The Amiga PCB Explorer is a browser application that was designed to assist people in various aspects of Amiga mainboard repairs. With this tool you are able to:
* Look up signal paths where physical traces have been damaged by battery acid or capacitor leakage.
* Find out which components are connected to the same signal net.
* Get a quick overview on chip pinouts.
* Locate any part on the PCB.
*Navigate around the PCB and marvel at its beauty :-)
Right now, the only available mainboard is the A4000 Desktop PCB (Rev B). Support for more boards may be added later.