Surf Champ: fixing the bonus reset issue

When I got Surf Champ the past owner had two main problems with it that caused him much frustration:  Sometimes the playfield wouldn't reset, and the 2nd player score would never roll the ten thousands.
The HUGE problem, as it turned out, was the 6B relay popping the 10A illumination circuit fuse.  That was a big investigation, and finally solved, and I have no idea if he was aware that the rollover switch was bent away, effectively hiding that wasp's nest.
The score reel issue was simple, cleaned and adjusted the contacts.

So the next big issue for me to tackle was the non-reset issue. 
I quickly observed that when the bonus was too large and the ball went in to the outhole, the game shot the ball to the shooter lane before reseting the relay banks and drops, effectively "saving" your ball.  i.e. you would keep your rollover and drops target process.

To get started, I inspected the relays list:

A few key ones:
K:  Bonus Score Relay.  Seems straightforward.
Q:  Game Over Relay.  I wanted to inspect this one because the game also ends prematurely due to this issue, even though the bonus fully countsdown.  (although not scoring entirely)
O: Ball Return Relay.  The issue starts when the ball hits the out hole, and the cycle ends with the ball getting kicked in to the shooter lane.

click to make bigger

My eyes went to the subtract bonus unit solenoid.  It is activated by the AX relay as part of the reset cycle.  Below that, it is entirely controlled by the K relay.  I thought this part was fine since even though weird stuff was happening, the bonus was being fully subtracted to zero each time.

CLICK TO MAKE BIGGEST

OK first let me gripe about these terrible reproduction schematics being sold at places like Marco.  The print quality is shit.  You can barely make out letters, especially not O vs Q.  Not because they are small, but because the printing is fuzzy.
And where there are fold lines, all the print has disappeared.  Gah. 

Remember with these schematics:  the switches are all in the state of ball 1 player 1, ball in the shooter lane.  so that means zero bonus.   To the left of the "Ball Return Switch" (the out hole) is a make/break switch for the zero position of the bonus unit. 
If there is bonus?  Activate K.
When there is no bonus?  Activate O.

Check the bonus unit switches:

This was our obvious culprit:  incorrect gapping at the top make/break switch.  Both side are making contact.  Thus when the ball hits the outhole, K is energized, and locks itself on until the bonus is at zero.

But O is also energized so when the motor is advancing the ball gets kicked out prematurely before the full after-ball reset cycle has been able to happen. 
K is locked on and not tied to a motor position, but much of the reset cycle is.

I cleaned and gab this make/break, and voila, the bonus is now counted properly.



Up next?  Well after solving the 6B issue, I have been enjoying the fine gameplay of Surf Champ.  Getting all rollovers hit to light the spinner and left/right rollovers is a big task, but a few things still weren't happening:
On the playfield itself it says:

When the rollovers are lit and the drops are down?  No reset on the drops.  No 5000.  And the bottom outlanes are not lit for Extra Ball & Special.

That would be relay 7B.  Not something that would have been used much, what with 6B being a trap to pop your fuses.
I did a quick trace on the schematics, and besides relay 6B being active, relay 7B needs a switch for all targets being down.   A quick glance under the playfield and I found this:

like an alien landscape

Like the relay 6B bar, this is another mechanical switch.  A bar goes across all 5 drops and when they are all down the little dark "T" shaped piece of metal recedes a tiny amount. 
The switch goes from open to... open?
I've never seen this style before, but you can see tiny drops of glue on either side of the "T" and one on the switch.  Obviously something had been there before and worn off.  A prior makeshift fix that didn't last?

I'm going to investigate that a bit.  Soon, I will have you, my extra ball!!!