AR amplifier repair

Hi, Gang,

I am trying to repair an AR amp that someone else started, the PS has been taken out already. I have the SM and update notices. I expected the 2 ~16 ga purple wires to be +/- 39V to the drivers & outputs. But when I visually trace the wires, and ohm them out, neither go to the collectors of Q19, Q20, Q23, & Q24. Nothing else looks likely. This should be trivial and I'm stumped - what are the 2 purple leads, please?

Thanks,
Frank