Hello,
I am relatively new to the EM machine restoration hobby. I am currently on my 4th machine. I am concentrating on EM shuffle alley machines (1950-60s). I find the machines on Craig’s list for approximately $300 in non-working condition. I then fix them up and pass them on to friends or siblings for the cost of the machine and materials. My paying job is a technical support engineer for BMW of North America. So far I have been able to fix all the issues on all the machines I have purchased except this one. The current one that I am working on is going to be a wedding present for my younger brother and it has one issue that I am unable to fix. I am hoping someone here will take pity on me and help me out. The machine is a 1968 United/Williams Delta shuffle alley machine. It was purchased in non-working condition and had not worked in years according to the previous owner. I have already gone through all the Step up Units to insure they functioned properly and cleaned out and renewed all the old gummed up grease. I have also checked all the switch adjustments on the machine (only found 3-4 that needed slight attention). I cleaned all the contact boards with a red scotch bright pad and put a light coating of Super Lube Synthetic Grease. I have also disassembled all the score wheels, cleaned of the old grease and reassembled without grease (metal to nylon contact = no grease needed). This fixed all the issues I had except one. The issue I have is that intermittently the #10, #6 and #2 pin coil latch plates will not stay engaged/locked after the main reset relay bar is activated. This happens intermittently and can happen to one, two or all three randomly. It happens most frequently to #10 (once every 3-4 resets on average). #6 is next (once every 4-5th reset). #2 happen once every 20-30 resets. So far I have done the following with no success.
Removed main reset bar, welded up elongated holes and re-drilled new holes in the proper location. Welded up and reshaped excessively worn stud on pivot bar that connects main reset plunger to main reset bar. Ensured that the main reset bar has enough travel and moves freely to reset coils properly. Insured main reset solenoid pulls plunger in far enough to activate main reset bay far enough to reset switch plates. Rechecked adjustment of all switches on Main reset assembly. Rechecked switch adjustment of all playfield contact switches. Rechecked all switch adjustments of pin tip up coil switches. Measured resistance of all coils on reset bar. All coils except the #1 coil were between 13.2-13.6Ohms (S-29 950 Light Blue in color). #1 coil measured at 5.4ohm (S-27 750 Green in color). I can see no reason why this coil should be different and the solder joint makes me think it was replaced sometime in the past. At this point I did not think the difference is significate enough to cause and issue and moved on.
I had someone else shoot the puck while I watched the main reset in action and I found that the coil plate for the #10. #6 and #2 pins would intermittently momentary lock in place and then seem to slip back out and not stay engaged. So the problem was that the coil would activate, the latch plate would engage but then immediately disengage causing my issue. I then removed the #10 coil, latch plate and switch plate and inspected them for excessive wear or damage. Finding no damage with the components I reassembled them and then connected an LED light bulb using alligator clips in a parallel circuit with the #10 coil at the coil connectors. I continued testing and found that when the coil worked properly the light would flash momentarily when the coil was activated and did not flash during the main reset operation. When the problem would occur the light would flash immediately following the main reset bar activation. This was an indication that I was getting a second voltage signal being sent to the coil releasing the coil plate immediately after the reset. Occasionally the light would flash dimly during the main reset activation but would not release the coil plate. This tells me that the voltage signal this time was not strong enough to activate the coil. This testing with the LED light was also done to the #6 and #2 coils with the same results. So the million dollar question is; what can be causing the secondary pulse causing the coil to activate and release/disengage the plate?? As a side note, when manually releasing the coil plates and then activating the roll over relay I was never able to get the issue to occur. It seems that you need to shoot the puck to get the pins to pop up for the issue to occur. I have attached pictures of the machine, Main reset assembly and a close up of #10, #6 and #2 coil plates in the released/disengaged position. I have the wiring diagram and playfield switch diagram.
I thank you in advance for any help you may give.
John
(Topic ID: 186872)
