Gottlieb Pro Football EM Pinball Repair (Problems and Fixes)!

Another video of the problems I came across while working on a Gottlieb Pro Football EM pinball machine.
If you enjoy these repairs and want to learn more about fixing EM pinball machines, I have created a beginner’s course with over 50 lessons!
troxelrepair.t...
**Special thanks to Fun with Pinball for the use of emSim (schematic drawing tool and simulator): www.funwithpin...

[@RearviewMirror-ij2pr]

Thanks for sharing! Would you go through troubleshooting from the start to finish for common problems, such as gi lights on but no game-ready?

[@waynegram8907]

TROXEL REPAIR, what are common EM timing issues? when EM games has timing issues how can you tell when an EM game has timing issues

[@troxelrepair]

I have another video (Gottlieb Sure Shot) that had a timing issue that was counting the bonus incorrectly. In essence, the pulse wasn't long enough to register one of the bonus points. Usually if it's a timing issue, it's probably going to be something with the score motor. Either a switch is letting go too early or staying on too long. This can cause problems with relays staying engaged or not engaged.

[@waynegram8907]

@@troxelrepair EM games that have Timing Issues, I have been told its the relays turning off/on that are Off Sync and not IN SYNC with the score motors CAM impulse switches/CAM Divots. I'm not sure what are the differences between CAM impulses compared to CAM Divots or they are the same thing just different names impulses/divots. But when an EM game has timing issues the CAM impulses/CAM divots are OFF SYNC with the turning off/off the voltage to the relays. I'm not sure what is causing the OFF Sync issues because the relays voltage will stay on for a millisecond or more even after the CAM divots/impulses have passed the rotation over the relay leafs blades. The store motor is turning in circles which the stores motors CAMs have divots which have nodes that will OPEN the relays leaf blades but the relays also have to turn off/on the voltages to the relays. So the relays voltages turning on/off the relays will have to be "in sync" with the store motors cams impulses/cam divots?