Greetings from Norway on this saturday evening!
I had two issues on my Williams Hot Tip (EM), one was that the ball #number lights in backbox were not working, all of them off, and that the shoot again light didnt work, probably a weak bulb holder issue as usual.
#1: I looked closer in the backbox and it seemed to be a (barely) millimeter gap between the wire which connects the 5 bulb bases to the jones plug base, so I jumper wired it.
#2: I bought some of the single LED boards for EM machines ( https://www.pinballlife.com/classic-bally-stern-insert-led-pcb.html ) and thought id just replace this bulb. I removed the playfield by unplugging the jones plugs to solder easier.
When i put the playfield back into the cabinet after these two fixed, and powered it in, something was not as it should. Barely any light, (though ball 1 number light was dimly lit), seemed like a power issue. When I started a game, the score motor seemed to run continuosly and nothing seemed to be able to start. Upon inspecting the area where the jones plugs were, I saw that there was a small wire lying there which looked like a jumper wire, but seemed unused. I then inspected the closest relay which is the Lock-Relay and found out that the plastic part where the lugs are attached was broken. The wires seemed connected, but it will definitely have to be replaced. I nudged it a little but, and powered machine on again and it was normal. when pressing start though, the light dimmed and motor started spinning.
Question: Could this be the culprit, that the machines/lock relay is struggling to pull in fully because its broken? It does not seem logical that my other fixed should cause this behaviour.