OK!! An auspicious start.
I assume you get 24.5 on C3 and -24.5 on C4 and C6?
Next step is to install the regs one at a time starting with the heater reg, the LV+ and then LV-. Before you install each reg make sure that there is no continuity between the metal tab on the regulator and the metal pins sticking out the bottom of the heatsinks. Also make sure that nothing on the output side of the regulators is accidentally shorted to ground.
And be sure to get LV+ and LV- in their correct spots.