I have been restoring a 1976 Playmatic Fandango. I have just fired it up after a deep cleaning. I have chased down quite a few simple playfield switch adjustments. Now I'm getting to the tricky ones. When the ball drains and goes into the trough. The bonus countdown sequence starts and seems to hang. The score motor runs and runs. The bonus stepper subtract coil buzzes and sometimes the ball return coil will energize and stay energized during this meltdown. The machine did this when I first bought it. I have since cleaned all the steppers and rebuilt the trough switches. I have been studying the schematic for this machine. There are many relays involved in this sequence. The schematic does not have much score motor sequence info. Has anyone been down this road before? Did Playmatic emulate Williams or Bally in the score motor design? If anyone can point in the right direction. It would be very appreciated. Cheers

Thanks HDC. I knew you would have the answer. You are the PLM tech guru. I checked the Bonus and Double Bonus relays they are clean and seem to make/break correctly. I did not think about the Triple B. I will check that. Half of the fun is getting the machine countdown with playfield up and no ball.

HDC, I think I'm getting a little closer. It seems to be a problem in a score motor stack. The schematic states that contact set "2B" breaks the bonus subtract coil. As I look at the #2 stack. I see makes and no breaks. It is a high state cam with one notch. I'm new to the EM world so I have a "Don't fix what ain't broke" approach to SM's. In this case I see a whole stack of switches that are in "make" for the whole rotation. I assume the stack has sagged or the rubbing block is worn. It seems if I lift the stack just a little. I get a bonus countdown like the game would do. I found this out a little late at night. I will explore this further at a better time. As I'm new to pinball repair I think I'm dealing with the extra step of setting up a good troubleshooting platform that a seasoned pro "just goes to". I arrived at shiming the ball in trough switch, pulling the motor service pin, then lowering the mains with a Variac to protect the coils. Yes my playfield is very nice as well. I did not realize how good I had it til I bought Mati Hari. I then came to know what a 30+ year old playfield looks like. Playmatic was on to something. It seems to make the play faster too. Thanks for all your help. Have a great day OSB

Update: It was the score motor stacks. I addressed several issues with this sagging switch problem.
I put a shim under 3 S.M. switch stacks. The stacks had lost their temper and would not open when on the high circle of the cam. Now the bonus counts down very nicely. I had some other problems where coils would buzz very loud. I now realize it was S.M. contacts not breaking and leaving coils energized.
I was mistaken, the #2 Cam has 2 detents. I actually knew that #2 cam has 2 events per revolution and #3 has 3, etc. It was late so I suppose my mind had gone to sleep before I had.
I guess it is time to clean and carefully arc those S.M. switch blades.
Thanks for your encouragement HDC. Getting a game going does take some time. It is like building a ship in a bottle. If it was easy, I would of tired of it long ago.