Last Saturday, whilst playing a house party, some drunk floozie stepped on the cord leading into my amp. This was between sets, so I had no idea until I came back to find the plug bent down at least 45 degrees from straight. I pulled the cable out, not noticing the the tip of the plug had broken off and was still in the jack. Tried to put another cable in and couldn't. Figured I had major damage, but finished the night through the active jack.
Well today I noticed the missing "head" on the cable and tracked it down, inside the jack. Try as I could, I just couldn't get the spring holding it in place to let it go. My solution: a bicycle spoke and some Gorilla Glue. Let it dry, pulled it out of the innermost spring clip, then used a tiny screwdriver to depress the outer clip and viola!
Just thought I'd share my unconventional extraction method and ask y'all about your crazy, but successful fixes...
