Logitech Z5500 : Centre Speaker Not Working

[KLiCK]

I have connected the Speakers to my Desktop

via the cables that came with the speakers itself

the green yellow and black wire

the thing is on Stereo only 2 speakers work and when in stereo x2 mode 4 wrks bt still not the central one

and only central one wrks on Dolby PLII Movie and rest all dont work then

can some one please help me out here thanks

 

[Udit]

change the switch at the rear of the control pod to 6 channel direct (move it up)

 

[KLiCK]

did that now only rear speakers are wrking along witht he woofer

the rest 3 are not wrking

 

[kunallkw]

the centre speaker would work , only when you activate PL2 or you are playing a 5.1 encoded material via 5.1 supporting sound card .