ok, here is what should happen.
with a mono cable plugged in straight to the amp, knowing the send is the tip, the OBEL jack should have sound on the OBEL side of the switch. On the Output side of the switch should be no sound. Volume pot will not work.
with a mono cable plugged in straight to the amp, the Output jack should have sound on the normal side of the switch. The OBEL side of the switch should have no sound. The volume pot will work. This is scenario is how a traditional guitar reacts.
Now knowing that the latter, or normal function, is not working with just a mono cable straight to the amp I am absolutely lost at how adding in the Junction box you get the volume pot to work. in the OBEL wiring the volume comes after the OBEL jack (send & return) before the output jack. in the normal wiring the OBEL jack is simply switched out.
Unfortunately, I can only point out that your guitar is not working as it should, and imho, the non OBEL side of it is not working correctly. after the 5 way, which is not wired correctly, the signal goes first to the buffer, then to the OBEL/NonOBEL switch where it either splits to the send out to the effects, thru them and returns to the guitar and/or to the guitars volume and then to the output jack.
or another way to look at it.
5way>buffer>Obel switch (Send & Return)> volume>output jack
5way>buffer>nonObel switch (jumper)> volume>output jack
IN the above when you plug that mono cable into the OBEL jack it gets it's signal at the send, so everything after it is not in the circuit but everything before it is.
when you plug that mono cable into the nonOBEL or Normal Jack you get nothing, aside from the switch there are only 2 components that are introduced into the circuit, the volume and output jack. Everything before the switch works as we know from the OBEL side.
from your video with only the guitar and amp it appears your problem lies somewhere after the switch, but the fact that the volume component works with the junction box points to some other anomaly I cannot troubleshoot without this all in-hand.
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