Or how one should never trust existing footprint libraries without double and triple checking everything!

This morning I decided to finally test the Computer with all cards inserted and... no clock! Not only did I swapped X1 and X2 on the CPU board, which was quickly fixed with a bit of copper and a sharp knife, but the CPU's Reset Line constantly was held high, at which the Clock Circuit of the CPU gets halted. After measuring a few times, checking the datasheet and the schematic of the switch, I found the reason why:

One would assume that the Reset Line is connected to 5V when the button is pressed. The footprint fitted perfectly to the switch I ordered on digikey, and even the symbol was nearly the same as in the datasheet. The only thing that I miss to check, and that could go wrong: Pins swapped!

In the actual datasheet, 2 and 0 are by default connected. Sadly the default library I found for it (Part "5501" in library "switch") has Pin 1 and 2 swapped.

I have to admit, that I rushed the creation of these PCBs a little, as I guessed that with the current COVID situation, shipping would get worse from China. In the hope to safe time by using as many existing libraries and parts, mistakes happend. Time to fix all 4 Buttons/Switches, but after that everything should work. Depending on the amount of errors, there will be a revision B at some point.