Hi all. I’ve got a machine I recently sold that is on location. With the purchase, I offered a one-hour comp diagnosis if any issues came up. That said, I threw two comp hours at this flipper issue and am out of ideas. Just trying to help these folks out even though they knew full well they were buying a 40 year old machine that would likely have some issues come up. I’m just trying to do the right thing.

Ok, so here’s what I did. Before selling it, (among a whole list of cleaning and adjustments) I replaced the power cord and installed a complete flipper rebuild kit. I had more than 50 plays on the machine before selling and everything worked great.

Now when I say the flipper is weak, I mean if ball hits from the base to half way out from the flipper pivot point, it seems to launch the ball well. When using the tip of the flipper, the weight of the ball only allows for ~3 inches of ball movement and the flipper struggles to complete the sweep.

What I did in the last couple days.
1. Checked the contact points from left flipper button and have them spotless clean and making good contact. Wires are soldered well at that switch.
2. Removed the left flipper coil and replaced with another of the same ohm resistance. (No change)
3. Swapped the left and right coils. (Issue stayed with the left flipper).
4. Cleaned all the Jones plugs (harness connectors) that follow the flipper wires for power and button switch.
5. Found a switch wire at the rear most jones plug (essentially under the backbox) was not soldered. Cleaned and then made a good solder connection. (Seriously thought that would resolve the issue, but no change)
6. Pull tested and visually checked every Jones plug connection in the circuit at the soldered points. (All we’re good)
7. Cleaned all the fuse contacts.
8. Unplugged all other powered machines in the building sharing the same electrical power source and tested the flipper. (No change).
9. Checked wire harness at the hold down points and near the coils on the “cabinet board” where the harness runs from the rear of the cabinet to the front... looking for wires that were worn through or burned. Nothing seemed irregular.
10. There is no contact between the flipper bat and the playfield, nor is there any binding issues under the playfield.
11. The flipper bat is tightly screwed to the coil plunger assembly.

The only things I can think of at this point is to assume there is a bad wire for the button switch circuit. And would need to run some alligator clip wires from the flipper coil to the other connection points. Or possibly just closing the circuit to cut out the EOS and the flipper button and everything else... checking every wire one at a time.
Second thought would be to move the transformer from 24 volts to the high line. Not sure that makes sense though.

I looked through the schematic and there simply isn’t anything else in this circuit that wouldn’t affect both flippers.

If anyone has some suggestions I would greatly appreciate it.

Thanks

Sorry the basics didn’t get included in the post. I selected the game title in the forum field but now that you pointed it out, I do t see it linked here.

1976 Williams Blue Chip

Hi all. Sorry for the delay we had some medical issues come up so I was just first able to get to the arcade tonight for the first time since you all made the above suggestions.

It was the EOS. The gap opened too soon and with a 2 second adjustment it was fixed.

I’m floored! Not that I’m surprised by all you, but because I spent three hours with the hood up previously and never thought in a million years bending the switch less than 1/8 inch would do anything.

You guys blow me away. Thank you so much for once again sending me excellent advice!