I'm trying to hook this surround system to my PC that has all six audio outputs for 5.1 but only get two speakers working. I think it really can only go up to 2.1 because of the lack of inputs but I'd like to think there has to be another way, any thoughts?
the manual does not include a diagram showing all connections on the rear (and i'm not sure which of those covered models you actually have).
from what i can tell it appears that it accepts composite (yellow, red, white) connections from other sources. this being only stereo inputs.
some HTIB (home theater in a box) sets are known for only allowing 5.1 sound from the integrated dvd/blueray players. this may be one of those models however i can not say for sure without seeing the back panel of your unit.
if you would please find a photo (on google images is fine) of your back panel that would help confirm. basically what i am looking for is either a spdif optical or spdif coax connection. i did not see it listed in the manual so i dont think you have one but double check on the back.
as far as what you can do? not much. you might have a sound mode which extends sound to the other speakers (but its still stereo sound).