Over-sensitive switches can trigger unexpected behavior.
Posted by Daniel Tonks on August 24, 2013 at 8:17 AM
At the beginning of a game, it’s traditional for a pinball machine to wait for you to plunge the ball at your leisure. I mean, that’s why the manual plunger and skill shots are there in the first place, right? However, some WOZ owners have reported that their game frequently auto-launches balls, without giving them the chance to do so manually. While this can indeed be the result of a physical issue that we’ll be discussing in this post, first make sure that what you’re seeing isn’t actually normal behavior.
As of the current game software (version 1.18), The Wizard of Oz should wait for you to launch the ball at the beginning of new balls (Ball 1, Ball 2, Ball 3), as well as on extra balls. However if you lock a ball, it’s completely normal for the game to auto-launch the replacement.
On a standard 3-ball game, expect only three chances to plunge the ball yourself (plus extra balls).
Now that we’ve cleared that up, if you feel your game is still launching balls when it shouldn’t be, then the most likely culprit is an oversensitive switch. Essentially, if any switch on the playfield changes state while a ball’s in the shooter lane (and this could be purely from the vibrations of serving that ball), then the game figures there’s already another ball in play and automatically empties the lane.
On my game these unexpected launches occurred infrequently, but enough to be mildly annoying. I figured the problem was likely some switch somewhere... but how could I find out which of the 113 switches in the game was the culprit?
Well, here’s a few ways I figured out – and why not add your own methods below as a comment!
- There’s clearly something wrong! Enter the two switch test modes, and look for switches marked “bad” (in red), or any that appear to be open (“inactive”) or closed (“active”) when they shouldn’t be. I believe the screen above should reflect a normal switch matrix.
- Play and listen! Many of the standup switches on WOZ correspond to unique sounds during gameplay. It’s by the constant barrage of “dinging” that I determined that my Glinda switch was oversensitive, without even needing to remove the glass.
- Get a bigger hammer! Enter the switch test modes and try banging on the playfield with your fist. Shake the machine. Switches extra-sensitive to vibrations may trigger, generating both an audio cue and an indication on the screen of which switch just activated. This is how I discovered that the first “T” in my “TOTO” rollovers was affected by strong vibrations.
- Easy does it... Switches should be sensitive, but not excessively so. In the matrix switch test mode (and, failing that, dedicated switch test), try lightly touching each standup or rollover switch with the tip of your finger and listen for the audio cue. Don’t actually push, just touch. It’s by this approach that I realized my Glenda switch wasn’t just too sensitive, it was actually in a state of near-constant closure. You can also use this approach to gauge the relative sensitivity of switches compared to others, which is how I noticed that my “Tin Man” rollover was less sensitive than the others – probably one reason why he’s always been the last character I collect.