I'm almost done restoring my 1968 Williams Doozie, but one problem still persists. Usually, when completing the X on the playfield, the game will advance the bonus (the 1 to 8 inserts shown in the pic below), score 300 points and advance the Advance Unit to change certain playfield bonuses and increase the 1-8 bonus insert (the 1 gets lit, then the 2 on the following X, etc etc).

image-3 (resized).jpg

My game only sometimes does this. More often than not, when the 5 targets get hit and reset, I only get 100 points and the Advance Unit does not activate. So to "work the problem" I'll go over the process of what happens when an X is complete to see if anyone can help me zero in on a solution. You can get the schematics here (https://www.ipdb.org/showpic.pl?id=704&picno=14506) but I'll also paste sections below. I also may be wrong in my reading of the schematics, so please let me know!

So it all starts when the 5 targets are hit, each on tripping a corresponding relay. Once all are hit, the 300 Relay is activated. This always works.

5relays (resized).jpg

Now the 5 Target Relay Bank always resets too, however, embarrassingly I can't find that on the schematics...

So now the 300 Relay is supposed to do 2 things, advance the Advance Unit and score 300 points...

But first it activates the score motor, it begins to turn.

score motor (resized).jpg

The 300 relay and impulse B on the score motor activate the 100 point relay for 300 points, which I don't understand. How does it pulse the 100 relay 3 times when there are 5 teeth on it! Not 3! There are five l̶i̶g̶h̶t̶s̶... teeth!

100 point relay (resized).jpg

impulse b (resized).jpg

The 2A wheel on the score motor and 300 relay with a closed trough relay active the Advance Unit

advance unit (resized).jpg

2a (resized).jpg

And bada bing bada boom, the score motor finishes its rotation (half round since it's a Williams I believe), the 300 relay is no longer energized because the 5 target relays have been reset, and it's all ready for another X to be made.

Now I've come into this hobby blind with no electrical experience at all, so I fall upon the mercy of the forum for guidance and wisdom!

Also, another clue which I forgot to mention, Doozie also has a trough gate, which allows you to get the ball back to the shooter. The ball triggers a roll over in the trough which, I believe, is supposed to score 300 points. This also does not happen every time.

MarkG Thank you so much for the reply! So to clarify, the 300 relay will activate every time, however it will score 100 points when it doesn't score 300 points.

I took a look at it today, and I manually activated the 300 relay. When I just click the leaf switch it sometimes completes the 300 points and advance unit. HOWEVER! When I press down on the leaf switch for more than a moment, it completes everything. Again and again, as long as you hold the switch for a second and a half, it completes.

This bastard

So the issue is that the 300 relay is sporadically not holding to be able to fully complete the cycle. Maybe the plate needs to be cleaned or re-magnetized or something. Thoughts?

@markg Oh yeah, I meant the plastic thing.

So I checked the 300 relay and it checks out

300 Relay (resized).jpg

I checked the drum unit cam 3, and it checked out

Cam 3 (resized).jpg

I even tested the connection between the transformer to the cam to the relay switch, and I got a nice clear beep from my voltmeter. Maybe it's something beyond that?

Circut (resized).jpg

I'm wondering if it's the relay bank. As seen below, does the white-b wire might head to the target relay bank then back again to the 300 relay?

Odd (resized).jpg

You can see in the 300 relay pic the red wire (on the schematics is the main trunk that eventually leads to the transformer) and the white wire with black tracer heading out from the relay itself and also a white wire with black tracer leading out from the leaf switch. They both look kinda yellow due to age.

white wire (resized).jpg

Thank you for the help!

MarkG I GOT IT!!

Sorry for the delay, been busy. We had extended family over, and the Doozie machine was a hit! It got tons of play!

Thanks to your recommendation of measuring resistance I found out that the CAM 3 switch didn't have a tight connection. Sure the voltmeter would make a beep when I tested it that way, however I found that resistance fluctuated. After tightening the switch stack, it now works reliably! 300 points every time! Bonux light advances! It's perfect! For my first pinball machine I don't think I could ask for better. Thanks so much!!

I've been done this one for a while now, but thought I'd show my work.

Before/After

I don't have much talent, but with the playfield and the cabinet repainted it looks a lot better.