回答“My headphone jack glows with a red light”NEVER use WD40 in delicate contact surfaces! This time, you were lucky because you got away with it. That stuff is purely for displacing water in hc applications, if you must use something in lc locations like this, then use contact spray such as Servisol S10. WD40 is a mixture of paraffin and DERV fuel. If you're running Mac OS on your MBP, then use a live Mint, Ubuntu or Debian usb stick and boot from that to access the required settings and enable all three drivers by selecting 2.1 analogue mode, this will then solve the problem if you're using Mac OS and changes will be saved. One question to those who poked or blew: Does the digital output come back up if you select digital audio out or connect a digital device? No red glow showing means that this ill-judged messing about has damaged the internal DAC which in turn means that the sound won't work nezt time you want to connect to a Tosh link or optical RCA device.