Quoted from alveolus:I was afraid a logic probe was going to come into play at some point
I will check when I get home, but will the voltages/current involved work with a logic probe? (Novice question)
Yeah - the plug at the motor control board doesn't even have to be plugged in (better if it's not, actually..). Essentially, the ground lead of the probe should go on something grounded (side rail, etc) and then check the two lines.. It will just report whether the line is high (driver off) or low (driver on).
For the clock, there are two drives, Forward and Reverse. If both drives are off (voltage high), motor will not run. If both drives are on (voltage low), motor will not run. If one is high, then the motor will run in that direction.
Normally, unless the game is wanting the clock to run, both drives should be off. The CPU controls the speed of the clock by pulsing the drives in the direction it wants the clock to run.
In test mode, the clock should NOT be running, until you go into Clock Test mode, AND select any test other than 'Clock Stopped'.
Direction Fast - Longer pulses.
Direction Slow - Shorter pulses.
It's impossible to test (in test mode, at least) the solid on running speed, which is the 'clock reset' speed after you drain or when exiting test mode or turning on the game. So if you're getting THAT fast motion, then something else is up.
You know, thinking about it - go into Flasher Test, and verify that each flasher flashes the correct flashers - ESPECIALLY the 'Gumball Machine High', '.. Mid', and '.. Low'. (#'s 38, 39, 40). I'm wondering if they're correct.