Mine has done this too...for the second time in 1.5 years.
Frustrating.
You have to request to buy thi coil from JJP, and you can't just buy the coil, because it's attached to part of the assembly.
So...you have to buy the assembly part.
1.5 years ago, it was $40 plus shipping.
I wish I knew a fix for this, so it doesn't happen again.

I have ordered the assembly and will install it when it arrives.
JJP did have me change the transistor that controls the drop solenoid.
It measured just a little different than the surrounding others...and they didn't think it was out of spec...but had me change it anyway.
That ground plane leg of the transistor was impossible to remove...I couldn't get enough heat to remove it...so I found another solution (jumped a wire to the ground). Yeah...I know...but didn't want to send the board out.