ok the question is simple: i must design a 4-bit shift register circuit. im pretty sure that for that, you'll need 4 D flip-flops sharing the same clock. right??

so i did that and here's the result (ignore the green box):

as you the led lights are neither completely off (0) nor completely on (1) rather they seem to be in this, uh, indifferent state?? anyway point is, its not working no matter where i put the switch

also its kinda funny (not really) but if i go to each ff and remove the preset/clear lines the circuit works! but i dont understand why is that an issue? why doesnt it just work the way i drew it?

I must design a 4-bit shift register circuit. I am pretty sure that I need 4 D flip-flops sharing the same clock. right??

So I did that and here is the result:

As you the LED lights are neither completely off (0) nor completely on (1) rather they seem to be in this, uh, indifferent state? Anyway, the point is, it is not working no matter where i put the switch.

If I go to each ff and remove the preset/clear lines the circuit works! but I do not understand why that is an issue? Why doesn't it just work the way I drew it?