Bally Solved Mr. & Mrs. Pac-Man Pinball (Bally, 1982) Drop Target issue

[Rusty]

At top of playing field is a bank of 3 drop targets. When all 3 targets are knocked down the targets do not reset. Upon further investigation when the center target goes down no noise is made so it is not registering. When I open machine & lift playfield I noticed that the switch behind the center target is missing what appears to be a resistor. It is black at top and rest of body is orange. The number 41 is on it. After doing more research resistors have more than 2 bands so I am a bit confused. Any help would be appreciated.

 

[Coil_Smoke]

Most coils and switches have a blocking diode wired across them. The diode is wired "Backwards" so it won't conduct when the circuit is active. The diode absorbs unwanted inductive spikes and noise generated when coils d-energize or contacts break(open). I think 41 refers to a case type. A 1N4007 diode should do the trick. I am a bit puzzled by your " center target goes down no noise is made so it is not registering" statement. Do any drop targets score points? Do the switches register on playfield switch test diagnostic?

 

[Rusty]

More Information

At top of playfield there are 3 drop targets. When game starts all 3 targets come up. When ball hits the 1st and 3rd targets the game makes a noise. When middle target is hit there is no noise. When all 3 targets are down they never come back up. I used paper (slide paper between switch leafs) to clean the switch and when game is on I tried to manually activate switch from inside with no luck. I verified the switch is making contact similar to other working target switches. I was hoping that the missing diode on middle target switch is causing the switch not to register. Game has new Solenoid driver and MPU boards. All other wiring behind drop targets appears to be in tact. Do you think that adding the missing diode will correct the issue or is there something else I need to focus on?

 

[Rusty]

playfield switch test diagnostic returns a zero so no switches are stuck. 1st and 3rd targets do score points but middle target goes down and does not score points.

 

[Coil_Smoke]

According to the IPDB schematic there is a diode inline with every switch in the matrix. These are not noise absorbing diodes. they prevent switches from interfering with others in the switch matrix. So that missing diode is required for the switch to be detected. A temp. jumper in that location should let you test the switch. http://mirror2.ipdb.org/files/1639/Bally_1982_Mr_Mrs_Pac_Man_Schematics.pdf