TASCAM TEAC M-3500 M-3700 Master D PCB 52103007-01

PCB From the M-3500, M-3700 be careful to check the board name and number on the rear as some here have same board name but different rear pcb numbers

This the rare Master PCB that has the talkback mike which if faulty is easy to replace but it has the Rare Oscllator switch that goes wrong, I have not found a replacement anywhere and your mixer is buggered without it, I have a big box of odd switch banks that maybe can be combined but not certain without original circuit configuration