Hello - I had the bias drift issue with my 1995 TSL100 and after replacing the main PCB with the latest version 20 the footswitch does not activate channel changes. I can change the channels no problem using the switches on the faceplate but as soon as I plug in the footswitch no changes are possible - it stays on the channel. I did the board swap myself, I labelled all the connectors and made sure they went into the right place on the new board. I took before and after pictures so I could double check my work. Has anyone run into this problem and could offer me some advice? Thanks!