These are multi-layer PCBs so you are not going to see all traces. That said the boards are 100% verified before being put up for sale. You can easily check the continuity of traces though with your DMM in “Beep” mode.
UPDATE: Check that you connected I and O if using a 3PDT wiring board or lugs 2 and 8 of a standard 3PDT switch to the actual TIP of both jacks. Use the GUIDE below to verify.
I hope that helps.