NuclearVision wroteGuys quick question!
I bought a case wwhich comes with 2 fans.
The back fan has a 3pin connector, from which emerges a second connector (molex).
The front fan only has a molex connector and no 3 pin.
My psu has a molex cable but i intend not to use it.
Can i plug the back fan 3 pin in the mobo and daisy chain its molex connector with the front fans molex connector to power the front fan?
Yes you can, it will work in the same speed as the 3pin fan.
what I think bobo619 was referring to is some fans are 3 pin while others are 4 pin, 4 pin fans are PWM fans meaning the power is sent in pulses. PWM fans are better for more sensitivity control over the RPMs and better suited for CPU and GPU fans most of the time.
DC fans just change the voltage in order to change fan speed and are not as sensitive as PWM. For example, a PWM fan possibly be made to run at 1431RPM exactly as the PWM is more manipulative that way, while a DC fan can run at 500 1000 1100 1200 etc etc. So it's more of an interval type.
Back to your question, yes you can plug your molex to the 3pin fan and have them both work together, it's fine.