I tried to simulate an RC lowpass circuit, but MultiSim doesn't quite provide the expected result.
Q2 being npn-type, and forward-biased, it should immediately turn on, becoming low-impedance on its collector-emitter path, so C3 should see almost GND on its lower terminal. On scope channel 'B', I have ~0,76V as expected, but channel 'A' carries a constant 5V where I would like to see a nice exponential.
p.s. There is no change in things if I pass an initial condition to the capacitor (IC=0V).
Any clues to what I did wrong?