Redwing buzz coil problem persists

[Redwing]

I tried a new capacitor with no luck. I cleaned and aligned the points, same results. I am now suspecting the coil but not sure how to test. Does anyone have a schematic for this buzz box?? Thanks in advance. I'm gonna go get a cuppa coffee...............................Daniel

 

[minh-thanh]

Can you take some pictures? because I don't know it
how to check the coil: with the high voltage coil, it is possible to check if it is broken or not, but it is difficult to check if it is short for a few dozen or a few hundred turns of the wire.
The simple way is to install new coil to test