Have you checked the voltages on the octave switch (they split the 4 V reference in four parts, so should measure 0, 1, 2, 3, 4 V). For the other pots, this might help:
Have you checked the voltages on the octave switch (they split the 4 V reference in four parts, so should measure 0, 1, 2, 3, 4 V). For the other pots, this might help: