I'm completely new to this hobby, having picked up a Royal Guard this past spring. Last summer the 10 score reel begin to intermittently act up and not register points. The problem got worse and worse so I took a look at it this weekend. I found that when I manually tripped the M relay for the 10 reel the bell would sound but some times the coil in the reel itself would not fire to advance the reel. I would often have to apply a little more pressure to trip both the bell and the score reel coil.
So I cleaned and adjusted the relay switch contacts so now the relay activates, the coil fires and the reel correctly increments each time the relay is manually tripped.
Thinking that I solved the problem I tried a game only to find that the problem is actually worse! The 10 reel now will increment maybe 1 out of 25 times. When a 10 point switch is closed by a ball the M relay and reel coil are firing but it looks like the plunger is not being pulled in far enough to engage the ratchet to advance the reel. So the plunger pulls in and goes back out and nothing happens. Yet when I manually trip the relay everything works fine, the reel advances every single time all day long! For some reason the reel only has an issue when its relay is tripped by a playfield switch, not when it's manually activated.
I checked the ratchet in the reel, it looks fine, does not bind and moves freely. Any help on this would be appreciated!