Concertmate MG-1 lower octave mod not working

[lordradish]

Hey, I know this doesn't get much play around here nowadays, but I tried doing the octave mod drop on my Concertmate MG 1, both by trying the switch method and the resistor replacement. I've followed directions, tried various resistors from 50-70k, and no luck. Most of them just modify it by a half-step to a whole step... I even tried some really low ones. Even ones that come close, I wasn't even able to remotely adjust the tuning/scale and have it work. Going through the forums, there also seems to be some dispute as to which resistor is even responsible, as the mod thread says R2/R28, yet seen other posts that say it is R4/R5, and should be replaced with 2meg resistors.

My plan was to put both the original values and the new ones on a switch, take the resistor off the board, and send the wires to both ends of the resistor holes on the board. I know it will work, but I can't do that if I don't know which resistors to replace, and with what. I've spent hours on this. Anyone help? THanks.