Help with a home theater system issue

Long story short my roommate has a surround system she got at Goodwill and I set it up for her but the internal amps are not functioning properly. It's only using the front two satellite speakers and sub which is independently powered. So it's 2.1 for now.

The front two speakers barely put out much sound even cranked to max volume. The sub is fine as again it's independently powered.

I've ruled out all settings, as there is a 2.1 output mode, and the radio is just as low so it's not an input issue. I have it hooked to her PC's output. I also have proper gauge speaker wire so that's not the problem either. I did hook up the center speaker to one of the front outputs too. Same deal.

So can an inline amp help at this point? Is there anything else I can try or rule out?

Also if this is not appropriate to post here in Tech I apologize in advance.