Ok, time to ask the experts...
First....I am no expert. I am the novice of novices.....that being said.....and reviewing just about everything on the website and going through the EBD manual, I have a problem that has stumped me. It is quite frustrating. I bought an EBD about 8 months ago. Was in a garage for a number of years. When delivered, the squawk and talk board was bad. Sent it out, was fixed. I installed it, everything was good. A couple of months later my upper left flipper started to activate at about 90 percent of the time. From there, it went down to 50 percent and then nothing. All I want to do is play the machine. Working endlessly on it is not my gig.
To date, I have been unable to get the upper left flipper to function.
From the diagrams in the manual, the upper left flipper is only activated when the left bottom end of stroke switch is open and the "dual" switch next to the first left end of stroke switch closes to power the upper flipper. The timing should be correct for all of this to function. I believe that this is correct. I can see the opening and closing happening when I have the playfield tilted up and the switch is depressed. During this test, the left bottom flipper always operates, so I know that the player control switch is ok. Diagram w-1192-28 in the manual show the set up.
I made sure that the contacts between all of the end of stroke switches are free of corrosion with fine grit sand paper.
I also made sure that there was no mechanical drag of the plunger going in and out of the coil.
(Yes, I know that some people want to change the type of flippers to earlier types of models.......those people can save their breath....I would throw the damn thing out before I go through those headaches. The flippers....as designed.....worked for 40 years. I see no reason to change the design now.) Everything looks fine there from the mechanical standpoint.
I then went to replace the coil. I thought that maybe the diodes were shot. When I did a quick test on my multimeter....one tested ok, the other did not.
After replacing the coil (my first time using a solder iron) ....guess what?.......no change.
If I take the return spring off the upper flipper (so there is even less mechanical force on the flipper), when I depress the left flipper button, the rod will fire into the coil (about 10 percent of the time).
Anybody have any ideas? (Remember.......novice)