Lionel shipped me a replacement board for my switch very quickly. Today I installed the new board and still have the same problem. I have poked, prodded, visually examined, and measured resistance for every connection I can think of checking.
I had previously tested the microswitches to make sure they were closing properly. For each microswitch I get the following results:
If the microswitch is closed, both show that the Yellow and Blue connections are shorted together. Yellow to Red and Blue to Red are both open circuits.
However, if the microswitch is open, I get different results. With one microswitch in the open position, The Yellow and Red connections are shorted together. Yellow to Blue and Blue to Red are open circuits. The other microswitch in the open position shows that Yellow and Blue are shorted together. Yellow to Red and Blue to Red are open circuits. Hmmm. 
I would think they would be identical.
I have checked very closely to make sure the solder connections on the microswitches are clean with no stray wire strands or solder connecting between terminals.
I am now thinking that one of the microswitches has its wires crossed. The switch used to work; I can't imagine what could have caused this. Can anyone confirm that the readings I am getting are not what they should be?
Looking at the Lionel Support website, it looks like Lionel calls these microswitches cherry switches. Under the exploded parts diagrams for the switches, it shows the cherry switch as part 3, but is unavailable. I did find part number 6102045318 for a 3 position cherry switch with wiring harness for Fastrack switches. Unfortunately, the photo doesn't show the microswitch (cherry switch); it only shows the wiring harness with the connector. Does anyone know if that is the part I need to replace the microswitches on my switch. If so, I will buy a few of them and replace both microswitches on this switch.
