Out of nowhere, there's a new problem. When the ball is sent up to the mini playfield to "battle the power", normally the flippers are supposed to be disabled and you can bang on the flipper buttons to silently activate the magnets in the mini playfield. Now the magnets and the flippers are actuating. But it's worse than that.
Test report says "Check switch 76 Mini P.F. exit". The machine thinks it has no way of knowing when the ball leaves the playfield, so it's only fair to leave the flippers on.
Checking switch edges. Good heavens! ground short on switch rows 4, 5, and 6!!
Row 4:
Row 5:
Row 6:
Wait a minute. It's column 4! Check it out:
Also not working: 76 Mini PF Exit, where all this started.
Column 4 is on J206-4 on the CPU board. Unplugged and replugged a couple times, no change. Have to leave this for now. What next?
Update
Stranger and stranger: completely disconnecting the mini playfield doesn't change things. Disconnecting the opto board mounted to the playfield (mini PF still unplugged) also didn't change things.
Holy crap. Serious ground problem. I thought the game was shocking me while I was removing the playfield, and sure enough there's 42V DC across the side rail and the power ramp, both metal objects which should be totally grounded. This is with the game off.
(Discussion under way at rec.games.pinball)
Posted by spblat at January 30, 2005 11:14 AM