[Kenwood] auto tuner trouble on 850

[WW3S]

I took the tuner apart today to see why I was having trouble on 40m. To
recap: the tuner works fine with any of my antennas on any band except 40m.
On 40m, no matter what antenna or even a dummy load, it seeks to find a
match and finds it when you press the tune button. Trouble is,, when you go
to transmuit, it must see a mismatch because it trys to tune again. It never
"latches" the tune.  I took the tuner apart and looks like L110 got very
hot....the core is black and most of the enamel seems burnt off the wire.
I'm assuming this is the trouble? Everything else looks ok. Is it possible
to damage a core by heat? Anyone know the core material? It doesn't appear
that it would be difficult to wind my own...or could I just disable the
relay that switches that coil in and out?