Volume switching between headphones and media (Classic Q20 Verizon)?

So if you guys could help me out it would be great, I plugged my phone into my aux cord in my car and the cord got real hot and the sound stopped. I unplugged the cord and noticed that the volume was constantly switching between headphones and media volume even though there was no headphones plugged in.
It does it all the time even in calls so the phone is virtually useless for calls atm.
Things I have tried:

messed with TTY settings
Cleaned jack with q-tip
Cleaned with needle
Unplugged headphones in and out (idea I read somewhere)
Pulled apart the phone and disconnected the jack
Factory reset

I'm worried I wont be able to fix it, and I have only had this phone for a year... any help or ideas would be great thanks!

Also I bought a replacement jack but have not got it yet, I would have thought disconnecting the headphone jack would fix the problem but it must be worse than that I guess

bump, any ideas guys?

Bump, still looking for answers, thinking of going with the Blackberry Incident-Based Support for smartphone users for help, how good is their support?

Bump, any ideas?

If your cord got hot, there was a short somewhere. It sounds like there was damage to your phone if it thinks something's plugged in when it isn't. Definitely try replacing the jack if you have the soldering skills, but if that doesn't do it there could be damage on the motherboard.

Passport SE, "The BlockBerry" - Cricket Wireless

Thanks for the reply, luckily the jack actually plugs into the motherboard so that makes it easy but my guess is that there is motherboard damage, because it still has the problem with the headphone jack unplugged. Is there anyway for me to send it to blackberry to get it fixed?