Hi and thank you for your help!
I followed all your instructions in order, so:
Already I isolated all the parts that could make contact between them and the case with tape isolated.
Then, I checked all the points of continuity with the diagram of Barry, everything is good except the connection between the RING of the jack IN (mass of the pile) and all the GROUND.
I wonder if I have not reversed something in my RING / TIP connection on the IN jack.
I put a picture and you will tell me what you think.
So I continued my tests with the power supply sector 9V instead of the battery to have adequate contacts.
Then I checked that Bi goes to In PCB and Bo goes out of the PCB, it is the case and there is good contact but what do you call the “little T”?
I checked that the TIPs of the IN and OUT jacks make good contact, that the SLEEVE also. Its good.
There is also contact between I and O on the 3PDT.
Then I checked the switch, I have good contact on 1/2, 4/5 and 7/8 in effect mode and 2/3, 5/6 and 8/9 bypass.
I took the measurements of the transistors, I have with the power supply connected:
C: 5.82 V / B: 1.07 V / E: 1.75 V
C: 1.08 V / B: 1.75 V / E: 1.10 V
I took the measurements without the transistors with only the sockets:
C: 0 / B: 0 / E: 9.35 V
C: 0 / B: 9.35 V / E: 9.35 V
So I think there is a problem because it does not correspond to the values shown on the diagram.
As I had two new transistors, I tried to redo the tests but the values are the same.
I redid the welds at the jacks, I put pictures for you to see if it looks good.
Finally, I connected S4, S5 and S6 to D1 on the 3PDT and finally I have the LED that works!
But I tested the rest connected to the amp and the guitar, still no sound, even bypass …