Thank you so much for all the help. I've reached out to the Polk Audio and they have me disconnect the speaker and connect it to my receiver with speaker wire. The speaker does work so they said it's the amplifier plate and to replace that, it'll cost me around $280. The subwoofer is about 10 years old. For that much money I could get a new one but if I can get this to work without spending that much cash, it'll help me a lot. SimpleGuy, I will definitely checkout that diode.
Again, thank you all.