How can I fix my computer speakers without paying money to get it fixed?

Ok, I have kind of a big problem with my computer speakers, my Compaq computer speakers stopped working one day when I was trying to fix my computer monitor because it wouldn't properly come on. It finally works after I keep everything off and then, somehow, my speakers malfunction to not work. I fooled around with cords in the back of the big computer modem to fix the monitor and I don't know what I did to it to get it to not function. The speakers are Compaq, but I have no idea what make it is. I even tried adjusting my other speakers where my Compaq ones were. Is it possible to get my other speakers working or to attempt to get my old ones working? The compaq ones would obviously go in the back of the big computer modem thing (the thing to cut it on), because the compaq speakers require a USB type outlet to work, and I'm thinking that the other speakers need the same thing to work for my computer.
Make and Model for other set of speakers
Make:Manhattan 120
Model:Sound Source