The signal sent from the control board passes through the SN74HC541 of the backplane and then sends it to the next stage. Now it is found that when the control board is powered on and the bottom board is not powered on, there will be a leakage current through the SN74HC541 string on the VCC of the bottom board, and there is a voltage of about 1.4V, in this case, the pull-up (control board power control) at the buffer output has no effect.
So I would like to ask if there is any measure to prevent leakage current from the IO string to VCC.
