Headphone jack not working.

[cracksauce]

A few days ago I began hearing some strange high frequency noises coming from my internal speakers, and even higher noises when headphones or my external speakers were plugged in. A day later, the noise was only coming from the internal speakers and the headphone jack no longer works. I have the speakers plugged in and the sound still comes from the internal speakers with intermittent high frequency noises and whistling. I'm trying to get back my speakers or headphones in working order.

 

[DeltaMac]

Is this the same MacBook Pro that you already posted about this same issue?
If your internal connection is failing, then the fix is to get that repaired.

You can find out if your external speakers or headphones are OK by trying them in another device with an audio output.

The MacBook Pro might need the left I/O board (which includes the audio out port), which would likely be $150 - 200 for a replacement. By your symptoms, I think that will be the culprit. But, if that doesn't fix it , then the logic board may need to be replaced, which will be considerably more expensive. Take to an Apple service shop for a better guess about the cause (and a good quote for the repair).