I recently picked up a 79 Flash (my second pin) and am having some difficulties with the left slingshot. The pin had been treated somewhat poorly previously, for instance there were womens hair ties in place of rubber all over the darn thing. As well as ugly fixes here and there on the back of the playfield, and completely warped/cupped inserts across the pin. Someone had also introduced the 'mini' ball for the tilt sensor into the playfield for a 'multiball' effect which the seller stated 'didn't work properly'
Anyway, when I got it the left slingshot coil was frozen, upon removing it I could see it had completely melted (or at least the sleeve did). The solenoid fuse did blow at least, and upon replacing it all the other solenoids work as expected. I replaced the coil with a new one, but it never triggers when the switches are activated on the playfield.
Next up I tested for voltage and got around 23V on it and the other solenoids, so thats good. So then I grounded the new solenoid on the non-banded lug and it fired, but it stuck on immediately -- which is probably how the last one melted. For some reason I freaked out at that moment and then grounded the other lug which unstuck the solenoid.
So now I'm not sure where to go from here. The 'special solenoid' transistors visually look fine, as I partially expected one to be visibly blown but was pleasantly surprised. To be frank I probably don't want the switches to 'work' until I figure out why the coil stuck in the first place (and continues to do so when grounded). In a nutshell:
1. Left slingshot coil was melted
2. Replaced coil, solenoid won't fire when switches are hit on the playfield
3. Grounding the non-banded lug fires the coil in question, but it sticks on at that point.
4. In solenoid test mode, this coil doesn't fire