I've spent about 3 hours googling every combination of what I can think of and I'm hoping it will jog someone's memory here.
As a child I remember watching a movie on TV (it was older at the time) probably somewhere between 1994 and 1997, but I never got to see the whole thing. This is what I remember about the story.
The characters were human, I'm not sure they were on Earth, but a similar planet. It was set in the future, but the premise was they discovered or stumbled onto a huge lost ship with technology that was better than what they had. It was definitely a "b" movie and seemed kind of similar in story to the "Andromeda" TV Series with Kevin Sorbo.
I can't find anything that seems to be similar and I read about 30 movie summaries on IMDB and Wikipedia. I don't remember any of the actors and I was about 10 at the time, so this is all I can remember. I was hoping to find it and share with my wife.
Edit: Adding more information as requested to the best of my ability. The people who found the ship were not prisoners, but my recollection is that they were normal(ish) people kind of grinding out a meager existence (kind of post apocolyptic). It definitely was not Sphere. I've seen that one all the way through several times, including once recently.
This story struck me as almost like a b movie version of the Andromeda TV series (which didn't exist yet). Thank you to everyone posting ideas.