Since you are using a battery, you need to plug a 1/4″ plug into the IN jack to activate the power. You said you have power to the board. The power must reach both boards. Confirm that you have power to all transistors. Provide voltage measurement for all legs of the transistors and the supply voltage.
If you do not have voltage to all transistors, carefully reflow all solder joints. Since you did not use SOCKETS on the transistors, you may have damaged one or more of them.
SIgnal must pass through jumpers. For all features to function, you need to install jumper wires on J1, J2, J3 and J4. I can’t see all of these on the photo. Confirm.
The status LED is not working because you have it installed on the main board. To use the LED on the main board, you must wire S4, S5 and S6 to the foot switch. A 3PDT board is not used. When a 3PDT board is used, the LED is installed on that board and S4, S5 and S6 are not used.
I cannot see if the blue wire from the 3PDT board BO pad is connected to the IN pad with a “T” on the main board. I think it is there.
Make these corrections and report back.