Headphone Jack not detecting External Speakers

Hello,

So yesterday this crazy loud noise came out of my external speakers on my mac... now the sound is coming out only from the computer speakers even when my external speaker are connected.

When the External speakers are connected there is this humming sounds coming out but the audio is still only coming out from the computer speakers. I tested the external speakers and they still work.

Any ideas? I'm affraid if i bring it to the Apple Store they will say it needs a new logic board or something crazy.