Help, finding the problem.

[GVC]

I am still new at this (three builds LPB2, Distortion Plus, Tubescreamer) and all of my builds thus far have worked.  However, my luck has left me with little to no trouble shooting skills.  I am now working on a DOD 250 and the bypass signal is fine but there is something wrong with the effect signal.  I have checked all of my connections and values to no avail .  Could anyone point me in the right direction for finding the problem with a faulty circuit and or component, articles and pointers with multimeters?

I have done some searches but most of the posts are piecemeal or digress into debate rather quickly.

[Hal]

audioprobe.