I did each filter alone and they work fine, but when they are made together to form a bandpass filter with the same components I used they don't work.
The output on the oscilloscope is a very weak signal that is similar to the output signal when the circuit is not fed with electricity (I guess it's negligible environment noise) while the input is a sine function from the function generator. Am I missing a middle stage or something? I tried all frequencies from 1Hz to 3MHz and nothing changes, even changing the amplitude of the input has no effects.