Beaker wrote
There's no telling what that switch wiring might result in, but you need a SPDT on/on switch. If you are using a 3PDT on/off switch the same as your bypass switch, it's not going to work right at all.
<snip>
...with a 3PDT numbered like this:
1 4 7
2 5 8
3 6 9
But the main thing is that your switch needs to be on/on.
I don't understand what you're saying, Beaker. 3PDT stomp switches
are on/on. There's no such thing as 3PDT on/off switch.
Making assumptions about what the lugs are attached to, the solo switch looks like it's wired correctly, with a solo indicator led on the 2nd pole. But those assumptions could be wrong.
The fault sounds like it's caused by a wiring mistake somewhere, possibly on a pot or ont the bypass switch, but it's too difficult to trace the wiring from the pictures. What would help: at least one clear photo the entire top of the board, at least one clear photo with
all wiring visible, individual photos that make it clear what the wires on the pots and the switches are connected to. Voltages are a good idea too.