Location: Parker, Colorado.
Symptoms: Machine not resetting, points not registering, drop targets not resetting, bad light socket, and various other problems.
This is the rarer electro-mechanical version of this pinball machine.
On most EM machines, you can disconnect the credit subtract coil to put the game in Free Play mode. However, on this machine, there are switch contacts on the credit subtract lever that trigger the Start Relay (S). I bypassed those with a wire.
Next, the relay coil spring on the Reset Relay (AX) had been previously replaced with the wrong one that was much weaker. I traded the spring from the Hold Relay, where the spring tension is less critical, to the Reset Relay and then re-adjusted the contacts. This fixed the problem with the machine not resetting correctly.
Next, many of the point scoring relays such as the 500 point and 5000 point were not holding though a cycle of the score motor. They are all common and routed through the normally closed Motor 2B switch. This switch was simply out of adjustment.
One of the formed switch blades had broken off the score motor and a replacement was obtained from The Pinball Resource.
Some of the contacts on the player unit needed to be cleaned and adjusted, which is a typical problem with Gottlieb multi-player machines. The bonus stepper unit was gummed up and not advancing or awarding bonus. It was cleaned and rebuilt.
The spinner switch needed adjusting because it was scoring points with just vibration from the playfield.
After replacing a broken light socket and spraying the back side of the backglass with Krylon Triple Thick Clear Glaze (to help stabilize the paint and keep it from peeling), the machine was looking and working great!
Hi. I am so glad I found your site. I am the proud owner of 3 – 70’s EMs. And I am constantly fussing with one or the other as you can imagine. Did you ever hear of a bonus unit solenoid (1972 King Kool – Gottlieb) staying engaged? I have checked all the playfield features that trigger the bonus but none looked stuck closed. Can you recommend where I should look next? Thank you so much!! ~Nancy
There is probably a relay that controls the bonus unit. You’ll need to look at the schematic. I don’t have one.