With 3ds off or on CLK = 2.3V.
i do not understand: measure the voltage of CLK in your fake SD with 3ds on?
i think i know what you mean, with 3ds on i measure on the 3ds sd card cable:
DAT3 = 3,3V
CMD = 3,3V
CLK = 0V
DAT0 = 3,3V
With 3ds sdcard connected to my board en put CLK, CMD and DAT3...