Update: I also see it is wired incorrectly to the 3PDT wiring board.

You need to wire from the Main board to 3PDT – BI, and BO.

Then from 3PDT –  I and O to the Jacks.

You have done the opposite.

So with power to the PCB there is power.

Work on the LED issue later. (You need to pick an LED location.)

I am not sure you are reporting the voltage to the JFETs correctly.

When looking straight down on the JFET and the top orientation is the same as the letter D 

The top pin would be D for Drain. You are reporting 0v for Drain. It should be around half the supply voltage as you adjust the Trimmer associated with its JFET.

Make sure your supply voltage to the PCB is just a little over 9v. (Measure it with your DMM)

Once you get the Bias correct, or close, fix the wiring as nothing will work without that being correct. You should try to push the wiring through the PCB till it comes flush with the PVC and then solder on the opposite side the same as you would a capacitor or resistor.

Good, now you have the correct readings and proper voltages for the JFETs.

Do you have sound in Bypass mode?

Is there sound in bypass?

I am glad to help.

The reason I was asking about Bypass sound is because if you cannot get Bypass then either the wiring is not correct or proper contact not being made by the connection. The latter could be a bad solder joint or just plain lack of contact.

You can easily test your contact points by using the Continuity Tester on your DMM.

The following image shows some important areas to test. (Some may not be identical as the guide is old.)

The best thing to do is use all of this as a valuable learning experience.

If you are getting another one, you can continue to test on this one.

Advice:

Before soldering wires to Jacks, or switch lugs be sure you have a strong mechanical connection first. Then solder. Also when soldering make sure the solder melts into the joint so it is not a ball sitting on top of the joint.

When redoing wire connections on a PCB pad it is not always necessary to clean the pad out with a tool. You can strip a new proper section of wire to be inserted and then while heating the back of the pad you can slip the new wire section through using the existing solder. It takes a bit of practice and some dexterous fingers.

Finally here is a video I made a long time ago.

It’s designed with beginners in mind, guiding them until they gain confidence. I demonstrate how to preheat a pad with time, which you can shorten as you improve. The intention is to support beginners, so hopefully, it will be beneficial.