I want to repair a cellphone headset that stopped working. Seems there
was a short near the jack (i.e. the signal clips in and out if I wiggle
the wire where it meets the jack). Does anyone know the wiring
diagrams for these types of headsets (it's a JABRA Ear Boom if that
helps)?

The jack itself is 2.5mm and the headset has a speaker, mic, and a
function button. I stripped down the outer insulation and used an
ohmmeter to try and trace the wiring. There's a green metallic wire, a
red metallic wire (wound around what appears to be a piece of string),
and a green insulated wire. Inside that wire is another green
insulated wire (goes to the tip) surrounded by a copper sheath (that
goes to the sleeve). I can't find anything wired to the ring. Any
thoughts on where I start?

Thanks