Do i/c's on a component affect overall system ?

My question is that do interconnects on one component affect the sound of another component the same way power cords will mix and give a system an overall sound. I know that if I change the power cord to my tuner and the tuner is off, the sound of my CDP changes due to the difference of the characteristic of the power cord mixed in with the rest of the system. Do i/c's change the overall sound of a system even if not listening to that particular component and in fact the component with the different changed i/c is off? I changed the i/c's to my preamp from my tuner and my CDP sounds different even when the tuner is off. Is this normal? I know it is normal with power cables. I should mention I just got my preamp back from repair and I realise that it must be burning in new parts but the change in sound when I changed the i/c's on my tuner has me asking this question.