Big problems fixing PC speakers

[Shakezilla]

Hi, I hope this is the right place for something like this, and if it isn't maybe someone can point me in the right direction. 

I am trying to fix a set of pretty nice PC speakers. I cannot get the right speaker to work properly. It has the Power and Volume knobs housed in the right one. The speaker itself works great, I re-soldered the right speaker into the left side and it worked perfectly so I know the speakers themselves are fine. I took the housing apart to check the solder joints and the positive on the right looked a little loose from the main board so I replaced both of the wires. I now have new wires soldered to the + and - leads on the main board. I soldered the wire to the speaker and thought it was good to go. The left speaker and the sub work perfectly. The right is super quiet. No matter what I try I can't get the speaker to work proper. I had the - from the board running to the + on the speaker and vice versa (not knowingly) and it still gave out a faint audio signal. When I wire it properly it still gives just a faint audio signal. My solder joints look good and I'm still getting barley any sound... It's starting to drive me up the wall so I'm hoping someone with more knowledge than me can help

Thanks