OK, this is a REALLY quick and dirty web page showing how to double up the ground on your Rollergames magnet board. This board caused me all sorts of trouble, because it would intermittently grab the ball. Every time I thought I had a 'fix', the game would run fine for twenty games and then all of a sudden it'd miss a few times in a row. I tried everything, even including replacing the magnet coil and pole itself!
Below, you'll see the magnet controller board we're talking about. It sits right below the six team lights, if you have the playfield in the up position. You can't miss it; it's in the middle of all the red arrows. (Your game will not have red arrows.)
On the left side of the board is the input (power, ground, signal), and on the right side of the board is the output (power and ground to the magnet). We're interested in adding a second ground to the left side connector.
The position is obviously important! As wired from the factory, there should be a key pin, and also an empty position. Our added ground fills that empty position. It's pin 2, if you're looking at the board or the schematics.
Note that I originally did this as a quick hack to test the idea, so I was using intercom wire. That's not normally good enough to handle much current, so I used four intercom wires, and twisted them all together, so that's why it looks kind of funky. There is no advantage to doing it this way; it's just the wire I had laying around that was convenient.
Next up, the other end of the ground wire! I just quickly loosened a screw that held the cabinet ground braid in place, and looped the wires around. Yeah it's hoakey; one of these days when I have nothing better to do I'll go back and make it pretty. (sh'yeah, right. And monkeys will write Shakespear, too!)
Finally, plug your connector back in, and you're all set!
It should be noted that I literally had replaced everything on that board before I got around to doubling up the ground. Every connector, every component (yeah, all three of them), and every plug. I was at my wit's end before I stumbled across this fix!
That's it! Takes five minutes, and my magnet has never failed to catch a ball since!